The state of Australia's youth detention system has been described as a "national shame" as further evidence emerges of harsh treatment of teenagers at a troubled Perth jail.
National Children's Commissioner Anne Hollonds says a taskforce is needed to fix recurring problems in youth detention, adding she is pushing the attorney-general to raise the age of criminal responsibility.
"This should not just be left to be a states' issue," she told ABC Radio on Tuesday.
"We need a national approach just as we've taken, for example, with domestic violence."
Her comments came after more proof of brutal treatment at Perth's Banksia Hill Juvenile Detention Centre was revealed.
Video of a teenager being subjected to the use of a hogtie or folding-up technique - considered to pose a risk of suffocation or death - was broadcast on the ABC's Four Corners on Monday night.
The technique involves a person's arms and legs being forced against their head and officers using their body weight to restrain the individual.
The practice was outlawed in Queensland in 2017, while the Northern Territory royal commission into the Don Dale Youth Detention Centre found it posed "significant risks of injury or death".
Ms Hollonds said she was shaken by the fresh reports of mistreatment but added they were no different from the "horrors" of Don Dale.
"What we need now is accountability for action," she said.
The WA Department of Justice has said prison officers were only authorised to use the folding-up restraint as a last resort when there was a safety risk to staff or other detainees.
Four Corners also revealed a council of attorneys-general report, finalised in 2020 but never publicly released, recommended lifting the criminal age of responsibility nationwide to 14.
"They know the truth that locking up young children does not keep the community safer ... we need to get on with this now," Ms Hollonds said.
"This is an absolute national shame."
The children's commissioner said she had contacted Attorney-General Mark Dreyfus and other ministers to raise issues about the youth justice system in the hope of seeing a federal-led approach to fixing the ongoing issues.
"I'm hoping now that we may be able to actually have that conversation about what we do nationally to transform youth justice in this country," Ms Hollonds said.
A report released on Tuesday also highlighted high youth incarceration rates in Queensland, which the Justice Reform Initiative said had more children in detention than any other state or territory.
The vast majority of the youths in custody were yet to be sentenced.
Executive director Mindy Sotiri said building more prisons, as the Queensland government planned to do with its proposed $500 million youth prison expansion, did not deter crime or rehabilitate offenders.
A group of organisations including Amnesty International, doctors groups and the Law Council of Australia has been campaigning for the criminal age of responsibility to be increased to 14 in all states and territories.
Royal Australasian College of Physicians president Jacqueline Small said more needed to be done to ensure children weren't incarcerated for behaviours that were a direct consequence of their young age.