Western Australia is being urged to provide greater support for mentally ill prisoners after several suspected suicides in recent months.
A report by Human Rights Watch has labelled the state's prisons "damaging and deadly" for people with mental illnesses, particularly Aboriginal and Torres Strait Islanders.
But WA's prison chief Tony Hassall has hit back, saying his department has brought an additional 50 clinicians into the system over the past three years despite the inmate population falling.
HRW examined the deaths of eight mentally unwell WA prisoners, including six Aboriginal people, between 2015 and 2020.
It found shortcomings in all eight cases, including two which remain before the coroner.
HRW has called for better screening of prisoners, greater cultural engagement and less use of solitary confinement.
It says WA authorities have focused on reducing access to potential self-harm tools rather than therapeutic interventions, a claim rejected by the corrective services commissioner.
"I totally disagree," Mr Hassall told AAP.
"We've put more psychiatric services in, we've put more clinical psychologists in, more counsellors.
"There's been a significant investment both in terms of staffing and infrastructure over the last three or four years."
Mr Hassall said WA's prisons managed more than 800 people with a mental illness on any given day.
He highlighted the opening of dedicated drug and alcohol rehabilitation prisons, a major planned expansion at maximum-security Casuarina, and investment in additional mental health support beds at Bandyup women's prison.
An analysis of coroners' inquest reports between 2010 and 2020 by HRW found that about 60 per cent of people who died in WA prisons had a disability.
More than half of the deaths were attributed to a lack of support provided by the prison, suicide and violence.
The Department of Justice last month established a taskforce to review the handling of at-risk prisoners and staff training after three apparent suicide deaths.
"I've asked for it to be an action-focused taskforce," Mr Hassall said.
"I don't want to produce a very lengthy report with lots of recommendations and then send it up to government. We will actually fix things as we go."
Among the deaths reviewed by HRW was that of a 19-year-old man, who had anxiety and depression, at the privately-run Acacia Prison in July.
The family of Stanley, whose full name is not used for cultural reasons, said authorities had refused requests to transfer him to another section where he had older family members.
His sister Jacinta was "inundated with distraught relatives" at a memorial ceremony who said they had tried to warn guards about Stanley's condition.
Another Indigenous man, Jomen Blanket, died at Acacia a year earlier after telling his mother he intended to harm himself - something she relayed to prison authorities.
Acacia's private operator Serco declined to comment on specifics of either case but acknowledged the hurt and sorrow of the men's loved ones.
A spokesman said Acacia had a clinically trained mental health team which was supported by multi-disciplinary services including prisoner welfare support.
The prison has reviewed its at-risk monitoring system and recently brought in two Indigenous mental health support officers. A further three mental health support officers are being sought, with two of the positions filled so far.
Lifeline 13 11 14
beyondblue 1300 22 4636
Australian Associated Press