The Woomera detention centre opened in the southern Australian desert in 1999. Within six months it held nearly 1,500 people, most from Iraq and Afghanistan. A third of detainees were children.

The centre led human rights groups to condemn Australia's punitive asylum seeker policies as protesting detainees sewed their lips closed on hunger strikes and attempted mass breakouts.

It was closed in 2003.

Last week, Australia's High Court ruled the government was not immune from compensation claims for immigration detention found to be unlawful.

Shine Lawyers said on Friday the Australian government had agreed to settle a class action by 38 former detainees who allege serious harm while they were held in immigration detention in the Woomera and Baxter centres.

"Today is an important moment, but it is also one marked by grief. Some group members did not live to see this day," said Nicholas Kitchin of Shine Lawyers.

"For many group members, Australia is now home. They have built lives, families and communities here, while continuing to live with the consequences of an extraordinarily trying chapter in their lives."

A Home Affairs department spokesman said the matter had been resolved "in accordance with legal principle and practice".

After closing the desert camps, Australia shifted to deporting asylum seekers who had arrived by boat to camps in the remote Pacific islands of Nauru and Manus Island as they waited for refugee claims to be processed.

Separately, human rights group Refugee Action Coalition on Friday urged the government to medically evacuate a 36-year-old Kurdish-Iranian refugee sent to Manus Island in Papua New Guinea in 2013, saying his mental and physical health had significantly deteriorated.

The group released photographs of the emaciated condition of the refugee, Hatam Yekta, in Port Moresby, where he has been hospitalised.

"Hatam's condition is an appalling example of the plight of the 10 or 12 refugees who are suffering serious mental health problems as a result of their mistreatment in Manus Island detention," said Refugee Action Coalition spokesman Ian Rintoul.

Australia's government says Papua New Guinea's government is responsible for the management of refugees remaining in Papua New Guinea, after an arrangement to process asylum seekers there ended in 2022.