Western Australia's Aboriginal Legal Service has slammed the state government for the ongoing use of lockdowns in Banksia Hill youth detention centre despite a Supreme Court ruling in August that the practice was unlawful.

ALSWA had taken the government to court representing a client who was locked in his cell for at least 20 hours per day on 26 occasions in Banksia Hill across four months in early 2022, while aged 14 and 15.

Justice Paul Tottle ruled the lockdowns were in breach of WA's Young Offenders act 1994.

On Thursday ALSWA chief executive Dennis Eggington told National Indigenous Times that in addition to the litigation that the service has undertaken, ALSWA lodged 23 complaints between February 2022 and November 2022 about conditions in Banksia Hill.

"ALSWA has also sent one complaint directly to Department of Justice - People, Culture and Standards on 6 October 2022 and another three on 23 January 2023," he said.

"A further eight complaints were lodged on 8 February 2023."

Professor Eggington said the "shameful failure" of the government to respond "in any sort of meaningful way" to Justice Tottle's decision in 2022, to the recent sentencing remarks of Children's Court president Hylton Quail, and ALSWA complaints about conditions in Banksia Hill reflect "the awful truth that WA government has consigned young Aboriginal people in detention to the too hard basket because there are no votes or political capital in treating them in any sort of humane manner".

"While Mark McGowan engages in predictable but profoundly cynical attempts to deflect blame for juvenile crime on Aboriginal families and communities, conditions in BHDC remain dire and young people continue to be subjected to barbaric treatment and conditions," he said.

Professor Eggington listed the poor conditions including extensive recent lockdowns, excessive use of force, young people sleeping in wet clothes/bedding, clothes and cells being extremely dirty, officers using degrading and unprofessional language, and young people in distress and experiencing thoughts of self-harm and powerlessness.

"It is hard not to think that ALSWA's complaints are sitting at the bottom of some government filing cabinet gathering dust. As the government sits on its hands, does nothing and offers lame excuses for its failings, the suffering of young Aboriginal people in detention is immeasurable," he said.

Last week Judge Quail sentenced a young repeat offender, days short of his 18th birthday, to an adult prison rather than have him face the conditions at Banksia Hill.

The Children's Court president noted that he had inspected the detention centre on 1 February and found "every child was locked down for the whole day".

"With the number of kids that were in Banksia that day, they needed 44 staff to open up and run programs. They had 21," Judge Quail said.

"It wasn't just that day and the day before and the day before that and the day before that… Now, the Government keeps saying they fixed this. Well, that's the reality."

Judge Quail noted that the boy had spent time in solitary confinement in Banksia Hill on multiple occasions, almost around the clock for days on end, when incarcerated on remand, despite Justice Tottle's ruling last August.

The Children's Court president said he chose to have the youth serve his latest sentence in an adult prison because he was close to becoming 18 and because of "the dire conditions in Banksia Hill and because there are no vocational programs".

The West Australian reported that while the boy was detained at Banksia Hill he accessed psychological support on five occasions but another eight sessions were "unable to be facilitated due to operational constraints", and he only received 291 hours of schooling in the nine months to October 3, an average of just 7.5 hours per week.

A Department of Justice spokesperson told The West it would not be appropriate to comment on statements made by the judiciary during court proceedings.

"More generally, staff at Banksia Hill Detention Centre and Unit 18 endeavour to provide the maximum out-of-cell hours for young people in their care," he said.

"Periods of lockdown, either to their unit or their cell, are necessary from time to time to maintain the good order and management of these facilities. This includes incident and/or behaviour management.

"A number of initiatives have progressed at Banksia Hill and Unit 18 to maximise out-of-cell hours for each young person including the recruitment of 85 new youth custodial officers in 2022 and an additional 40 commencing training this month."

While regular out-of-cell hours at Banksia Hill are meant to be 11 hours and 15 minutes a day, an answer from Corrective Services Minister Bill Johnston to a question in parliament last week revealed there were 981 occasions a Banksia Hill detainee spent at least 20 hours in lockdown between August 25 and November 20, 2022.

It also emerged there were seven suicide attempts at Banksia Hill and Unit 18 in November alone 2022 alone.

Questions in parliament from Greens MP Dr Brad Pettitt last year exposed the fact there had been 36 self-harm attempts and one suicide attempt in Banksia Hill in July and 13 self-harm attempts and three suicide attempts among the small number of children held at Unit 18 in just three weeks, from July 20 to August 8.