It’s coming up to the 30th birthday of Australia’s policy of mandatory immigration detention for non-citizens who do not hold a visa. Throughout its lifetime, the policy has remained a controversial cornerstone of Australia’s migration law framework, facing – and withstanding – multiple High Court challenges.

AJL20 v Commonwealth is the latest of these challenges. By a 4-3 majority, the High Court found that, in some circumstances, the Migration Act 1958 (Cth) authorises prolonged detention, even where the executive has breached key statutory obligations.

In this post, I look at the history leading up to the High Court’s decision, and the key points of difference between the majority and minority judgments. I then explore what the decision means for the law on extended immigration detention, and the people subject to it.

AJL20 and the road to the High Court

AJL20 is a 29 year old Syrian citizen, who migrated to Australia in 2005 on a child visa, and lived in the Australian community for nine years, In October 2014, following a three year sentence, his visa was cancelled on character grounds under s 501(2) of the Migration Act. This converted him from a ‘lawful non-citizen’ (a non-citizen with a visa that entitles them to be in the Australian community) to an ‘unlawful non-citizen’ (a non-citizen without a visa).

Section 189 of the Migration Act imposes a non-discretionary obligation upon Department of Home Affairs officers to detain unlawful non-citizens. Consistent with this, AJL20 was taken into immigration detention. Section 196 provides that an unlawful non-citizen who has been detained under s 189 must be kept in detention until they are either granted a visa, or removed from Australia (which must happen as soon as reasonably practicable if visa channels are exhausted).

AJL20 applied for a protection visa, on the basis that he was a refugee who would face persecution if returned to Syria. The Department found that this was true, and that, under international law, Australia owed him non-refoulement obligations (obligations that prevent a country from returning a person to a place where there are reasonable grounds to believe they would face persecution). It advised the Minister that, because of these obligations, it would not be possible to remove AJL20 to Syria, and that if he was refused a protection visa he risked facing indefinite detention. The Minister noted this advice, but refused to grant AJL20 a protection visa, on the grounds that he did not satisfy the character test.

Relevantly, the Department’s advice to the Minister was incorrect. Section 197C of the Migration Act provides that once the duty to remove an unlawful non-citizen from Australia is engaged, Australia’s non-refoulement obligations are ‘irrelevant’. It was therefore wrong to say that the consequence of refusing AJL20 a protection visa would be indefinite detention, rather than removal to Syria.

The Department’s advice, and the Minister’s decision, reflected a government policy to avoid refoulement wherever possible, in spite of s 197C. This policy has been in place since 2014, when s 197C was inserted into the Migration Act. It reflects a trend in Australian migration law to attempt to avoid being bound by courts to comply with international law obligations, but without entirely dispensing with them as a matter of practice.

In Federal Court proceedings in 2017, AJL20 (under the code-name ‘DMH16’) argued successfully that the policy of indefinitely detaining unlawful non-citizens who are owed protection obligations ran counter to the clear words of s 197C. Justice North found that because the Minister acted on the incorrect understanding that indefinite detention would be the consequence of denying AJL20’s protection visa, his decision to refuse the visa was affected by jurisdictional error. The visa refusal was quashed, and AJL20’s protection application was remitted to the Minister for redetermination.

In December 2018, a delegate of the Minister made a new decision to refuse AJL20’s application for a protection visa. In doing so, the delegate expressly acknowledged Department advice that the consequences of refusal would be continued immigration detention, followed by removal from Australia as soon as reasonably practicable, irrespective of non-refoulement obligations.

The decision to refuse AJL20 a protection visa did not automatically trigger an obligation to remove him from Australia. This is because there was still a channel via which he might feasibly have obtained a visa allowing him to stay in Australia. Section 195A of the Migration Act grants the Minister a discretion to grant any type of visa to a person in detention, if they think it is in the public interest to do so. This power was recently used to grant three members of the Murugappan family temporary, three-month visas allowing them to live, work and study in Western Australia. Similarly, it could have been used to provide AJL20 with a visa that would have allowed him to live in the community instead of in indefinite detention while removal options were explored.

In July 2019, the Minister advised AJL20 that he would not consider exercising the discretion in s 195A. From this point, pursuant to s 198, an obligation to remove AJL20 from Australia as soon as reasonably practicable arose. The combined effect of s 198 and s 197C obliged the Commonwealth to pursue removal at the earliest possibly opportunity, even if this meant that AJL20 would be returned to Syria, where he would face a real risk of persecution (in breach of Australia’s non-refoulement obligations).

Despite this obligation, the Commonwealth made no attempts to pursue removing AJL20 to Syria. Indeed, for several months it did not investigate removal options in any country. In November 2019, AJL20 commenced proceedings in the Federal Court, seeking habeas corpus on the grounds that the Commonwealth’s failure to actively pursue his removal demonstrated that he was no longer being detained for a permissible purpose. Shortly after those proceedings were commenced, the Commonwealth began to investigate the possibility of removing AJL20 to Lebanon. It continued to investigate removal to Lebanon until the Federal Court proceedings reached the hearing stage, but without any suggestion from Lebanese authorities that there were real prospects of Lebanon accepting AJL20. Evidence suggested that, throughout this period, the Commonwealth maintained the position that, due to Australia’s non-refoulement obligations, removal to Syria was not an option.

Initiating proceedings in the Federal Court was a high-risk move. AJL20’s lawyer, Alison Battisson, admits that it could have resulted in his return to Syria. But she also says that he understood what he was entering into, and was in a position where none of the alternatives were any better. In Battisson’s words, AJL20 fell into a category of people best described as ‘totally screwed’ – faced with an unfortunate choice between two bad options that violate international human rights law – being forced to return to a country where they would face harm or indefinite detention in Australia.

AJL20’s Federal Court gamble paid off. Justice Bromberg found that the Commonwealth had breached its duty under s 198 to remove him ‘as soon as reasonably practicable’ by neither investigating removal to Syria, nor demonstrating that Lebanon was likely to be the most expedient removal option. Consequently, Bromberg J found that AJL20 had been unlawfully detained by the Commonwealth, and that the appropriate remedy for unlawful administrative detention was a writ of habeas corpus. He ordered that AJL20 be released into the community.

Despite the Federal Court win, AJL20 faced an uncertain future. He was out of detention, but without a visa authorising him to remain in Australia he was still an ‘unlawful non-citizen’. This meant that the possibility of re-detention under s 189, followed by removal to Syria still loomed.

The Commonwealth’s response to Bromberg J’s decision was two-fold. It introduced new legislation, designed to shore up legislative support for its policy of detaining but not promptly removing people like AJL20, who were found to be owed protection, but who nonetheless had been denied a protection visa (see further discussion of that legislation here). It also appealed – successfully – against Bromberg J’s decision in the High Court.

The High Court proceedings

The Commonwealth went to the High Court conceding that it had breached its obligation under s 198 to remove AJL20 from Australia ‘as soon as reasonably practicable’. This meant that the only issue in the case was what consequence should flow from that breach. At the heart of the case was the question: what happens when the Commonwealth has a duty to remove a detainee from Australia as soon as reasonably practicable, but appears to be making very minimal attempts to remove them at all?

AJL20 argued that, in line with Bromberg J’s finding, the appropriate remedy in such a circumstance was a writ of habeas corpus. The Commonwealth argued that the only available remedy should be an order of mandamus to compel the Commonwealth to perform its duty of removal.

The High Court, in a 4:3 decision, found in favour of the Commonwealth. Chief Justice Kiefel, Gageler, Keane & Steward JJ, writing jointly, formed the majority. Strong dissents were delivered by Gordon and Gleeson JJ, and Edelman J.

Unpacking the High Court decision

To understand the differences between the majority and the dissenting judges, it is helpful to highlight two aspects of the Migration Act that sit somewhat in tension with each other.

The first aspect relates to the dichotomy that the Act draws between ‘lawful’ and ‘unlawful’ non-citizens. The Act’s stated object is to regulate, in the national interest, the entry into and presence in Australia of all non-citizens. Any non-citizen who holds a visa entitling them to be in Australia is a ‘lawful non-citizen’. Any non-citizen without a visa is an ‘unlawful non-citizen’. Section 189 obliges an officer to detain any person known or reasonably suspected to be an unlawful non-citizen. A fundamental difference, therefore, between lawful and unlawful non-citizens is that lawful non-citizens are at liberty to enter the Australian community and unlawful non-citizens are not. Section 196 requires an unlawful non-citizen to be kept in detention until they are removed from Australia or granted a visa. In other words, the Migration Act operates to keep unlawful non-citizens segregated from the Australian community.

The second aspect relates to the limits on immigration detention. While s 189 provides for the mandatory executive detention of unlawful non-citizens, the power to detain is not at large. Section 198 provides that once the obligation to remove an unlawful non-citizen from Australia is triggered, removal must be carried out ‘as soon as reasonably practicable’. There is also a constitutional perimeter, within which any executive detention authorised by statute must remain. A body of case law, commencing with Chu Kheng Lim v Minister for Immigration, Local Government & Ethnic Affairs, has confirmed that legislation authorising executive detention of a non-citizen will stay within constitutional bounds provided the detention it authorises is limited to what is ‘reasonably capable of being seen as necessary’ for a constitutionally permissible purpose (including removal, processing a visa application, or deciding whether to grant a visa). In Plaintiff M96A v Commonwealth the High Court affirmed that, in order to avoid infringing Chapter III of the Constitution, a court needed to be able to determine the lawfulness of the detention. This, they clarified, required the existence of ‘objectively determinable criteria for detention’.

The facts of AJL20 pressed directly on the tension between these two aspects of the Migration Act. An unlawful non-citizen was in detention, and was required to be removed from Australia. When the Commonwealth made no move to remove him, was it nonetheless lawful to continue his detention because, despite the breach, the Act mandatorily requires the detention of unlawful non-citizens? Or did he need to be released from detention, because the Commonwealth had failed to comply with the criteria – statutory or constitutional – that would make detention lawful? No prior case had squarely dealt with this question. Al-Kateb v Godwin dealt with a similar issue, but with key differences: s 197C had not yet been included in the Migration Act, and the Commonwealth was not unwilling, but unable to remove Al-Kateb, despite its best efforts.

The majority judgment

For the majority, the dichotomy that the Migration Act draws between lawful and unlawful non-citizens was fundamental to understanding the relationship between ss 189, 196 and 198. In their view, s 196 – which fixes the period of detention for an unlawful non-citizen detained under s 189 – gave effect to the binary distinction between lawful and unlawful non-citizens by providing that detention of an unlawful non-citizen can only end if removal occurs, or if a visa is granted.

The majority found that this scheme falls within the constitutional bounds available to the Parliament. They said that the scheme pursues the legitimate, non-punitive purpose of segregating unlawful non-citizens from the community while they are waiting to have visa applications processed and determined, or while they are awaiting removal from Australia. The majority said that involuntary detention of an alien for these purposes had been found to be constitutionally permissible in a string of prior cases, including Chu Kheng Lim, Re Woolley, Plaintiff M76 and Al-Kateb.

For the majority, the requirement under s 198 that removal be pursued as soon as reasonably practicable was relevant to the lawfulness of executive action under the Migration Act, but not to the lawfulness of detention. This stemmed from their finding that s 196 was a valid law made by Parliament, and that it created a duty to detain an unlawful non-citizen until removal or the grant of a visa occurred. The majority stressed that a breach of duty by the executive could not erase these duties, nor render s 196 invalid – if it could do so the supremacy of Parliament over the executive would be reversed, and the rule of law subverted.

The majority held that the available remedy where the Commonwealth fails to perform its duty to remove an unlawful non-citizen as soon as reasonably practicable is mandamus. They said that this enables the courts to exercise judicial power to give effect to the scheme provided for by Parliament, and enforces the supremacy of Parliament over the executive.

The dissenting judgments

By contrast, the dissenting judgments of Gordon and Gleeson JJ, and Edelman J both made less of the binary distinction between lawful and unlawful non-citizens, and far more of the aspect of the Migration Act relating to limits on immigration detention. The dissenters all emphasised that executive detention of an unlawful non-citizen is not automatically valid for all time, simply because it is carried out for the ultimate purpose of visa determination or removal. There are also limits on the duration for which the executive can detain an unlawful non-citizen. These limits arise both out of the text of the Migration Act, and as a constitutional imperative.

Justices Gordon and Gleeson noted that the central issue in the case was whether executive detention is lawful even if it continues beyond the time at which it should have ended. They held that, as a matter of statutory interpretation, s 189 prescribes a duty to detain unlawful non-citizens, and ss 196 and 198, read together, prescribe the duration of the detention. Consequently, when an unlawful non-citizen who is detained for the purpose of removal, such as AJL20, is detained past the point at which removal becomes reasonably practicable, the detention is no longer lawful.

Similarly, Edelman J noted that courts typically confine ‘open-textured’ statutory powers and duties, such as s 189, by reference to the subject matter, scope and purpose of the statute they are found within. Applying this principle, the detention authorised by s 189 needed to be read not only in light of the object of regulating the entry and presence of non-citizens in Australia, but also in light of the purpose of removing unlawful non-citizens with no visa options from Australia as soon as reasonably practicable, even if this would run counter to Australia’s non-refoulement obligations. He found that, because the Commonwealth’s ongoing detention of AJL20 detention was being carried out for the purpose of removal consistent with Australia’s non-refoulement obligations, it was not lawful detention under the Act. He noted that, to decide otherwise, would amount to upholding a purpose of detention that was beyond the scope of statutory authority, and would deny the supremacy of Parliament over the executive. He also noted that it was ‘at best misleading’ to describe the obligations arising under s 189 as a ‘duty’ to detain AJL20, when the executive had options available other than detention – such as granting him a visa under s 195A.

Both dissenting judgments also found that, to the extent that the Migration Act did provide that it was lawful for the executive to detain an unlawful non-citizen indefinitely, in breach of the duty to remove, it would contravene the Chapter III limits on executive detention identified in Chu Kheng Lim.

The dissenting Judges found that the appropriate remedy for the Commonwealth’s breach in this case was habeas corpus. Both judgments found that mandamus was also available, but that this did this not affect the availability or appropriateness of habeas corpus as a remedy. Justice Edelman found that mandamus to compel removal was the appropriate remedy when the Commonwealth had breached its obligation to remove a person as soon as reasonably practicable, whereas habeas corpus was the appropriate remedy for detention for an improper purpose. He held that both breaches had been made in AJL20’s case, and therefore both remedies were available. Justices Gordon and Gleeson noted that wrongful detention by the executive ‘compels the availability of habeas corpus’. They also noted that in a number of cases mandamus would not be a useful remedy. For instance, if the Commonwealth breached its obligation to remove an unlawful non-citizen because it had lost their file, mandamus to compel removal would not yield a practical result. Additionally, an unlawful non-citizen in detention may lack the means to obtaining the information necessary to mount a case for mandamus.

Where to from here?

AJL20 confirms, for the first time, that, where a person is an unlawful non-citizen under the Migration Act, their detention by the executive will be lawful until the moment that it actually ends, through removal or the grant of a visa. This is so even where the executive is breaching key obligations, and the period of detention is significantly lengthened as a result.

The case follows in the footsteps of another infamous immigration detention case, Al-Kateb, by pushing the boundaries of Commonwealth power over immigration detention out further than ever before, but by the narrowest possible majority. This is sure to raise questions about the legacy it is likely to leave – all the more so when one member of the majority, Keane J, is due to retire next year, and three of the youngest judges on the bench entered very strong dissents. Tied up in this are ongoing questions about the place of Al-Kateb (the majority pointedly noted that the correctness of its constitutional holding did not arise for consideration), and the Lim principle, which was given its sharpest teeth in years by the dissenting judges.

The immediate consequence is that AJL20 faces a likely return to prolonged immigration detention. The prospect of his return to Syria, however, has been taken off the table. In May, in response to Bromberg J’s Federal Court decision, Parliament passed a new law – the Migration Amendment (Clarifying International Obligations for Removal) Act 2021. This law maintains s 197C of the Migration Act, which says that Australia’s non-refoulement obligations are ‘irrelevant’ when a duty to remove under s 198 has arisen. However, it carves out exceptions that block removal for people, like AJL20, who have been assessed as engaging Australia’s protection obligations but denied a protection visa. These exceptions do not provide a durable solution for people in this category. Rather, they will remain in extended, potentially indefinite, detention, for as long as the Minister determines that protection obligations exist, and the Department determines that removal to a safe country is impossible. To borrow a phrase from Alison Battisson, they remain ‘totally screwed’.

Sangeetha Pillai is a Senior Research Associate at the Andrew and Renata Kaldor Centre for International Refugee Law, UNSW Law & Justice. 

Suggested citation: Sangeetha Pillai,AJL20 v Commonwealth: Non-refoulement, indefinite detention and the “totally screwed”’ on AUSPUBLAW (8 September 2021) <>