Lawyers representing hundreds of current and former detainees of Western Australia's notorious youth detention centre have filed a class-action lawsuit against the state government.
Sydney-based lawyer Stewart Levitt, who is leading the case, said the claim had been filed and accepted in the Federal Court.
He said the claim included testimonies from around 600 people who claimed they were mistreated while detained at either the state's only youth detention centre, Banksia Hill, or its predecessor facility, Rangeview.
"It alleges effectively … physical abuse, restriction, restraint, breaches of the Disability Discrimination Act and inhumane treatment," Mr Levitt said.
Banksia Hill was condemned by state Children's Court President Hylton Quail on multiple occasions this year in relation to the treatment of detained children.
Judge Quail has also criticised the ongoing detention of a group of juveniles inside one of Perth's adult prisons.
The facility was recently the subject of an ABC Four Corners report that exposed the use of a dangerous restraint technique the WA government subsequently announced would be banned.
Mr Levitt said claimants ranged from current detainees to adults who had spent time in the state's youth detention system as far back as 1997.
He said the case was "potentially worth hundreds of millions of dollars because there are so many people involved".
"We've been directly instructed by about 600 [people]," he said.
"The vast majority [are] Indigenous."
Mr Levitt said the group was seeking financial redress.
He said there were two lead complainants who were both 18 years old.
"A boy who has a mental illness and a girl who has autism," he said.
In the face of mounting pressure over the state's youth detention system, the West Australian government recently announced work was underway on a proposed on-country rehabilitation facility for at-risk youth in Western Australia's Kimberley.
That was part of a $40 million package announced in May to "tackle juvenile crime in the Kimberley".
That plan also included funding to expand the government's Target 120 early intervention program, which supports young people who are at risk of becoming repeat offenders.
Following the Four Corners report last month, the government held a meeting to address concerns in the state's youth justice system.
After the meeting, the WA government pledged an additional $63 million to improve Banksia Hill.
Mr Levitt said the next step of the class action process would be a directions hearing in the Federal Court.
He said the class action could take two to three years to complete.
A spokeswoman for the WA government said as the matter was before the court, it would be inappropriate to comment.
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