While the arbitrary detention of asylum seekers and refugees is a breach of international law, successive Australian governments have continued to detain refugees arbitrarily since a 2004 decision found it legal under Australian domestic law.

But that all changed on November 8 when the High Court ruled the practice was unlawful.

Following the decision, 80 people – refugees as well as people held by immigration for other reasons – were released immediately into the community, with at least 92 more eligible for release. Experts say 300 more cases could also be affected by the decision.

“This is a hugely significant decision, which will have life-changing consequences for people who have been detained for years without knowing when, or even if, they will ever be released,” Josephine Langbien, a senior lawyer at the Human Rights Law Centre, told Al Jazeera.

“People who have lost years of their lives may finally have a chance at regaining their freedom and returning to their families and communities.”

While Australia provisionally accepts 13,500 people each year for resettlement through the United Nations High Commissioner for Refugees programme, those arriving by other means – such as by boat from Indonesia – are detained in prison-like facilities.

Since 2013, Australia has implemented Operation Sovereign Borders, which the government describes as “a military-led border security operation.”

Detention in harsh offshore processing centres is another arm of this policy, which the Australian government says is necessary to assess refugee status and possibly grant a temporary visa.

However, Human Rights Watch, Amnesty International and other human rights organisations have long argued the policy contravenes international law including the UN Refugee Convention – which forbids arbitrary detention of refugees and stipulates that seeking asylum is not illegal – and the Convention Against Torture.

Critics, such as author and former detainee Behrouz Boochani, also say the aim of the policy is to create conditions so onerous that potential refugees are deterred from seeking asylum in Australia in the first place.

Langbien told Al Jazeera that on average, refugees have been detained for an average of 708 days either on the Australian mainland or in offshore detention facilities in remote islands such as Nauru.

“Earlier this year, the government disclosed that the longest period it had detained a person in immigration detention was 5,766 days – that is nearly 16 years,” she said.

In comparison, the United States holds refugees for 55 days, while in Canada, refugees are held for just two weeks before a decision is made on whether they can remain in the country.

‘Not prison’

The plaintiff in the High Court case was a Rohingya man using the pseudonym NZYQ who had been detained indefinitely due to a lack of deportation options. As a Rohingya, he cannot return to Myanmar where the mostly Muslim minority was stripped of their citizenship in the 1980s and targeted in a brutal military crackdown in 2017.

Controversially, however, NZYQ had previously been convicted of child sex offences, had been jailed and had his visa revoked.

Under normal circumstances, a non-Australian would be deported after serving a sentence for such serious crimes.

But because NZYQ was without citizenship when he was released on parole in 2018, the Australian government was unable to do so.

As such, NZYQ remained in detention with no realistic prospect of removal and it was this indefinite detention the court ruled illegal under the Australian Constitution.

“The court found that indefinite detention is beyond the constitutional limits of the government’s power,” said Langbien.

Langbien also told Al Jazeera it was important to recognise that while NZYQ had committed a serious offence, he had served his sentence and should be released into the community like any other offender would be under domestic law.

“Immigration detention is not prison,” she said. “These two systems [immigration law and criminal law] are and must be entirely separate. The constitution does not allow immigration detention to be used for punitive purposes. The Australian government has never had the right to use immigration detention as a way to punish people or to extend sentences.”

The decision overturns the 2004 precedent in the High Court case known as Al Kateb, which ruled a stateless Palestinian man’s indefinite detention was lawful within the realm of Australian law.

Yet, Langbien said this should never have been the case and that the ruling will extend to more than just people who are stateless, but to many who cannot return to their country of origin for reasons such as fear of persecution.

“The High Court’s decision will bring about the release of people who should have been released many years ago,” she told Al Jazeera.

“Everyone, regardless of their citizenship or visa status, has the right not to be unlawfully or arbitrarily detained by our government.”

‘A beautiful joy’

While there were celebrations as dozens of detainees were released, the abrupt freedom has created a new set of challenges for people who have endured the prolonged uncertainty of indefinite incarceration.

Hannah Dickinson, the principal solicitor and head of the Legal, Human Rights Law Programme at the Asylum Seeker Resource Centre, told Al Jazeera that the reaction from those who had been released was “quite extraordinary and very moving”.

“We’re receiving texts from our clients with pictures of them with their families. They’re driving home from the detention centre, finally, after 10 years separated. So there’s a beautiful joy.”

However, she added there was also concern.

“There is a fearfulness and also a pain arising from having been detained for that long and a worry that something is going to be done to take that freedom away,” she said.

Refugees who are released into the Australian community are often placed on restrictive temporary visas which include limits on work and are often subject to regular review.

Dickinson told Al Jazeera that visas issued to those released last week “had 18 conditions attached”.

“And they might be things like reporting conditions. They might be things like the type of work a person can undertake. And they typically include conduct conditions like not committing any criminal offending. They’re very comprehensive and quite restrictive in nature,” she said.

Ian Rintoul, from the Refugee Action Coalition, said the government has a responsibility to ensure a supportive transition into the community.

“The government can’t just dump these people, who have been held unlawfully for years, into the community without proper support,” he said.

“Indefinite detention has been a serious breach of human rights that has had devastating consequences including suicide and other self-harm attempts.”

Their extended detention means many of those held will find it difficult to establish a new life.

“Many have lost families and family connections as a result of the years in detention. They have lost income, lost years of possible study that has limited their life opportunities,” Rintoul said.

“Many of them have mental health issues caused by the years of unlawful immigration detention that will make finding work and holding down a job a real challenge.”

Minister for Immigration Andrew Giles would not comment on the future implications of the High Court’s decision, stressing the need to “ensure community safety is upheld”.

Among those released over the past week is Sirul Azhar Umar, who was part of the security detail for then-Malaysian Defence Minister Najib Razak and was sentenced to death for the high-profile killing of Mongolian translator Altantuya Shaaribuu. Sirul fled to Australia pending his appeal and while he was later arrested, Australia does not deport people to countries that maintain the death penalty.

In response to Al Jazeera, the Department of Home Affairs noted the full judgement had yet to be made public, and declined to comment on whether any legislative amendments would be made to close the legal loophole created with respect to the aim of Operation Sovereign Borders.

“The Department is currently considering the High Court’s orders and decision,” the department said in a statement. “The High Court has yet to provide written reasons for its decision, therefore it would be inappropriate to comment on the matter.”