Western Australia's corrective services commissioner has been replaced and a prison officer suspended following the death of an Indigenous teen who self-harmed in the youth wing at an adult prison.

Mike Reynolds will make way for Brad Royce, an assistant commissioner from WA Police, Corrective Services Minister Paul Papalia said.

Officers discovered 16-year-old Cleveland Dodd in the Unit 18 youth detention facility at Perth's Casuarina Prison on October 12, after he contacted them through the intercom.

He was taken to a Perth hospital in a critical condition, where he later died.

Mr Papalia said Corrective Services had been confronted by a series of critical incidents and crises over the past two years and juvenile detention was suffering.

"We need to reset, we need new leadership and we need a focus on cultural change (and) that's what we've done," the minister said on Wednesday.

"We've brought in a commissioner with known leadership skills, proven leadership skills and the capability of effecting cultural change and improvement across an organisation."

Mr Papalia also announced the creation of a new deputy commissioner role that will focus on youth detention.

It is yet to be filled and Mr Reynolds remains a WA Department of Justice employee.

The appointment of the new commissioner came as authorities confirmed that a prison officer had been suspended from duty pending the outcome of an inquiry into Cleveland's death.

The teen's death is being investigated by the Department of Justice and the coroner while the Corruption and Crime Commission has also begun inquiries following allegations of serious misconduct.

Cleveland was the first child to die in WA juvenile detention in the state's history.

The area where he was found, Unit 18, opened in July 2022 to house the most challenging juvenile offenders after major riots at Banksia Hill Juvenile Detention Centre.

Both facilities have been plagued by high rates of self-harm incidents, riots and detainees being placed into prolonged lockdowns.

Mr Papalia said the situation was improving at Banksia Hill but Unit 18 remained a problem.

"The juvenile detainees in Banksia Hill are out of cells, they're going to school, they're getting intervention, they're getting good service and it's improving all the time," he said.

"Unit 18 is not where I want it to be and I'm focused on making it better."

The state opposition said Mr Reynolds had been scapegoated by the government and corrective services was a "trainwreck".

Opposition spokesman Peter Collier said the agency had been "weaponised" for political purposes to show off the government's "tough on crime rhetoric".

"In the meantime, the lives of inmates, in particular juveniles, are at risk and that's a shame," he said.

"What has gone what has been lost in this whole ghastly episode is the fact that ... we are actually dealing with lives."

Premier Roger Cook previously said the situation at Casuarina Prison was not good enough.

"We've let that young detainee down and as a result of that we need to continue to learn and we need to improve," he said on Tuesday.

Rachael Ward - AAP