In the last five years 154 issues have been raised by children with the Western Australian ombudsman regarding the state's troubled youth justice system—most of them concerning the conduct of prison staff.

The concerning numbers were revealed in the Parliamentary Commissioner for Administrative Investigations' (Ombudsman) submission to the youth justice inquiry and comes in the wake of two Aboriginal children dying in WA custody in the last year.

In a letter to the Parliamentary Committee, Deputy Ombudsman David Robinson said between 2019 to 2024 his office received 131 complaints about 154 issues from or on behalf of 96 children and young people detained in youth detention sites.

Of the 154 issues raised, Mr Robinson said 100 resulted in outcomes for the young person concerned, including "disciplinary action taken against staff and/or the imposition of increased supervision".

"In some cases, staff were required to undertake training and/or counselling and other cases resulted in an apology and/or an explanation being provided to a young person," he said.

Up until 2022, this was solely from Banksia Hill Juvenile Detention Centre, before 'Unit 18' in the adult, maximum security Casuarina Prison was opened for some youth offenders.

Mr Robinson said of the complaints, 67 identified their age as between 13 and 17 and 19 identified they were Aboriginal and/or Torres Strait Islander.

"However, I note that a significant number of complainants preferred to remain anonymous, and identification of Aboriginal and/or Torres Strait Islander status was voluntary," he said.

Of the 154 issues complained about, 55 per cent concerned officer conduct, whilst 40 per cent was about the facilities and conditions.

Mr Robinson said officer conduct complaints included allegations of excessive force and "inappropriate or disrespectful language".

Complaints about the facilities and conditions concerned quality of food, cleanliness, lockdowns, access to phone calls and visit, and air conditioning.

There were also several complaints about health services and rehabilitation programs.

A Reportable Conduct Scheme (Scheme) began in January 2023, and expanded at the start of this year.

Despite its infancy, Mr Robinson said the reports to the Scheme - which includes significant neglect and emotional and psychological harm to a child, and with a threshold for various types of reportable conduct that differ significantly from a criminal and disciplinary setting - had received 29 notifications of reportable conduct from agencies who administer the youth justice system—all relating to custodial settings.

17 of the notifications concern Aboriginal and/or Torres Strait Islander young people (from government data, not self-identified).

The notifications include 23 allegations of physical assault (including allegations of the use of excessive force); four allegations of sexual misconduct; one allegation of a sexual offence; and one allegation of significant neglect.

Mr Robinson said 15 of the notifications had been closed and 14 are open and currently subject to oversight.

The numbers come as the youth justice system has come under heavy criticism, following the deaths of 16-year-old Yamatji boy Cleveland Dodd last year in Unit 18, and an unnamed 17-year-old teenager in Banksia Hill in August.

The inquest into Cleveland's death has seen a number of revelations brought forward, including the department lying about having specialist youth justice staff in Unit 18, and children only getting at most, eight hours out of their cells a day—two less than at Banksia Hill.

The longest serving Children's Court Judge in WA history, Denis Reynolds, told the inquest children being held at Unit 18, were routinely viewed as "inherently bad".

"At the core of the issue is a false premise," he told the court.

"In my view, they are vulnerable children. They have neurodevelopmental issues and have loads of trauma."

The latest Closing the Gap data showed Aboriginal children were incarcerated at almost 35 times the rate of non-Indigenous children in WA.

A report by Commissioner for Children and Young People, Jacqueline McGowan-Jones, found that, despite some improvements, "systemic problems" still remained, and the complex needs of children were not being met at Banksia Hill.

Despite this, Corrective Services Minister Paul Papalia - who has routinely said he can't comment on the ongoing inquest despite the litany of failures present - said the reason children are spending less time out of their cells at Unit 18 is "because of the cohort and their behaviour".

"It's a failure of their behaviour," he said.

Kurin Minang human rights expert and law academic Dr Hannah McGlade suggested In August Minister Papalia is not fit for the job, arguing "he is not capable of leading reform and he lacks the knowledge and experience – and it is not clear he has the commitment either".