Explainer: High Court ruling in NZYQ

On 29 November 2023, the High Court handed down a short, unanimous judgment in the case of NZYQ.[1]

This document responds to ‘Frequently Asked Questions’ relating to the High Court’s judgment and what is likely to come next. It is not intended as legal advice.

What did the Court decide?

The judgment reaffirms the principles expressed in the case of Chu Kheng Lim[2], which was decided twelve years before the High Court upheld the legality of indefinite detention in the 2004 case of Al-Kateb v Godwin.[3]

The Court confirmed the key constitutional principle in Lim: that detention is a form of punishment and can usually only be inflicted on a person by a court once they are found guilty of a crime. 

The Court held that a law authorising administrative detention of a non-citizen by the executive government would only be constitutionally valid if it was reasonably necessary for a legitimate non-punitive purpose. Ultimately, the Court held that the law authorising detention of the plaintiff was not adapted to the purpose of his removal, in circumstances where there was ‘no real prospect of removal from Australia becoming practicable in the reasonably foreseeable future.’

The Court’s judgment is a constitutional watershed. The orders pronounced by the Court on 8 November 2023 have led to the release from immigration detention of around 140 people.[4]

Who is covered by the judgment?

The judgment applies to a relatively small group of people in immigration detention who are subject removal from Australia after their visa has been cancelled or they have been refused a visa, but for whom there is ‘no real prospect of removal from Australia becoming practicable in the reasonably foreseeable future.’

People covered by the judgment fall into three broad categories: those who are stateless, have been found to be owed protection, or cannot be removed due to a practical barrier. The latter category might include people who are physically or mentally unfit for removal, or whose home countries will not cooperate with attempts to remove them. Whether the decision applies will depend on people’s individual circumstances, but it will be up to the Government to prove that some real prospect of removal exists.

Some of the people released have been convicted of, and served sentences for, serious offences. Some others have no convictions; have convictions for which they did not receive a sentence of imprisonment; or have convictions for which they served a short term of imprisonment.  

The Court has left open a question about more complex situations where people refuse to cooperate with removal efforts because of their fear of return, or other personal reasons. It is likely these situations will be the subject of further litigation.  

Will the judgment have any impact on the new bridging visa regime? 

Before the High Court delivered its reasons, the government had already legislated to introduce a regime of ongoing monitoring and penalties for people who were released because of the decision, some of whom had previously served criminal sentences. The Bridging ‘R’ visa regime introduced by the government on 16 November 2023 subjects all people released from unlawful indefinite detention, regardless of their individual circumstances, to 28 mandatory conditions restricting their conduct and movement.[5] The regime also allows the Minister to subject people to electronic monitoring and curfews; those conditions have been imposed on effectively all of the people released.[6] Breaches of conditions are a criminal offence carrying a mandatory minimum sentence of one year’s imprisonment.

As it was not part of the dispute before it, the Court did not express a direct opinion on the legality of the Bridging ‘R’ visa regime. But the Court made several observations that may be relevant to the resolution of a challenge to that regime.

The Court confirmed that the constitutional limits on executive power are concerned with ‘substance and not mere form.’[7] The Court referred to previous decisions in which those limits had been employed to invalidate punitive legislation outside the detention context – including recent citizenship-stripping cases.[8] In analysing whether a law served a legitimate and non-punitive purpose, the Court directed attention to ‘that which the law is designed to achieve in fact’.[9]

These observations reinforce the critical importance of identifying what the Bridging R visa arrangements are intended to achieve ‘in fact.’ In challenges that have already been filed, the Court will be required to determine whether measures such as electronic monitoring and curfews are inherently punitive in character, such that they may only be imposed by a court following a finding of criminal guilt. Even if it is accepted that the Bridging R visa arrangements have a legitimate purpose of community protection, there is a further question of whether the measures are appropriate and adapted to that purpose. 

Did the Court ‘endorse’ the creation of a preventive detention regime?

No. The Court was not asked to provide a general opinion on what should happen to people who were released, nor did it do so.

The dispute before the Court related to the constitutional limits of executive detention. The Court reiterated the serious limits on the circumstances in which a person might be detained. It made the point that detention is punitive, and it is ordinarily reserved as punishment for a crime, imposed by a court.

The Court made it clear that the government could not create a scheme for the detention of a non-citizen, based solely on their legal status as a non-citizen. It made it equally clear that the government could not legislate to create a scheme that would allow non-citizens to be detained merely for the purpose of segregating them from the Australian community.

Certain media reports have fixed on obiter (or passing and non-binding) comments made at the conclusion of the judgment relating to the circumstances in which the plaintiff might be taken back into detention.

There the Court observed that its orders did not amount to the grant of a visa to the plaintiff, or a permanent immunity against any kind of detention. The Court observed that the plaintiff may be placed in immigration detention again in future, at the hypothetical point that his removal became practicable. This is because, if that point is reached, immigration detention would be justified for the purpose of facilitating removal.

The Court further observed that its orders did not prevent the plaintiff from being detained subject to some other applicable statutory scheme, such as a law ‘providing for preventive detention of a child sex offender who presents an unacceptable risk of reoffending if released from custody.’[10] Schemes for the preventative detention, or continued supervision, of high-risk offenders after completion of a prison sentence already exist under State laws and are subject to different constitutional limitations. The Court’s reasons should not be read as suggesting that a new scheme is needed.

If the government were to introduce a new preventive detention regime, it would need to comply with the constitutional limits articulated by the Court in this and other cases. It is doubtful that such a scheme could validly allow for detention imposed unilaterally by the executive government. If a preventive detention scheme was administered by the courts, it would need to comply with various limits in order to serve a legitimate protective purpose, and to be appropriate and adapted to that purpose.[11] For instance, existing State schemes are limited to protecting the community from serious danger; require a high threshold that a person is shown to present an unacceptable risk; require specialist evidence of the risk posed by the person; and require periodic review.[LJ1]  Importantly, existing preventive detention orders can only be imposed if the person has been convicted of certain serious offences.

But more fundamentally, there is no justification for a separate scheme that would apply to this small group of people. Everyone should be treated equally before the law, regardless of their visa status. This is even more critical when basic rights such as liberty are at stake.

The government is not free to detain non-citizens at will, or to create another punitive detention regime to replace the one that was struck down.


[1] [2023] HCA 37 (NZYQ).

[2] (1992) 176 CLR 1.  

[3] (2004) 78 ALJR 1099.

[4] Guardian, ‘Another 45 people released due to High Court ruling on indefinite detention as Coalition plays hard ball on ‘patch up’ bill’ 27 November 2023 https://www.theguardian.com/australia-news/2023/nov/27/indefinite-immigration-detention-high-court-ruling-45-more-people-released#:~:text=On%20Monday%20the%20Australian%20Border,electronic%20monitoring%20ankle%20bracelets%20applied.

[5] Migration Amendment (Bridging Visa Conditions) Bill 2023.

[6] SBS, ‘Court releases decision behind immigration ruling, as government admits detainee missing’ 28 November 2023 https://www.sbs.com.au/news/article/government-confident-about-locating-missing-detainee-who-refused-ankle-tracker/67afehp5s.

[7] NZYQ [28]

[8] NZYQ [39]

[9] NZYQ [40]

[10] NZYQ [72].

[11] See Garlett v Western Australia (2022) 404 ALR 182; Fardon v Attorney General (Qld) (2004) 223 CLR 575.