An ABC investigation has revealed that the senior officer on duty the night Cleveland Dodd attempted to end his life was lying down in his office with the lights off, partially undressed, when the Indigenous 16-year-old boy was found unresponsive in his cell.

Late last month it emerged that an officer was allegedly asleep on the night in question and had been suspended.

Earlier this week, the ABC reported a series of errors took place on the night, and that despite two unmistakably clear warnings to officers that he was going to take his own life, those on duty failed to prevent it.

On Wednesday, the public broadcaster revealed the senior officer on duty appeared to be napping when another officer who found Cleveland went to retrieve the keys to open his cell. Once alerted to the situation, the senior officer was then seen buttoning up his shirt and sitting down to put on his shoes.

He then reportedly strolled towards Cleveland's cell with his hands in his pockets.

In addition to suspending the officer, the WA Department of Justice has referred the matter to the Corruption and Crime Commission.

In the wake of Cleveland's death, Western Australia's corrective services commissioner Mike Reynolds was replaced by Brad Royce, an assistant commissioner from WA Police.

A number of problems exposed by the ABC's investigation are expected to be internally investigated, including the covering up of CCTV cameras by detainees, the filling of welfare checks in advance by officers, and the fact Cleveland was occupying a cell that was damaged - containing a defective vent which he used to attempt to take his own life.

The camera inside Cleveland's cell was covered by a strip of toilet paper for close to 12 hours, before his suicide attempt, meaning he could not be seen by officers, but no-one on duty appears to have made an effort to remove it.

While officers are meant to complete physical welfare checks every 15 minutes, either via the CCTV or in person, it emerged earlier this week that Cleveland's cell check form had been completed up until 6am that day, despite him being taken from the prison before 3am in an ambulance in a critical condition, suggesting it the form had been filled in advance.

It is understood, according to the ABC's latest report, that the conduct of the other staff members on duty that night is also being examined.

The revelation came as WA Aboriginal justice advocates slammed Corrective Services Minister Paul Papalia's "parliamentary theatrics" as "a new low".

Late on Wednesday the Aboriginal Legal Service of WA described Mr Papalia displaying "weapons" in parliament allegedly made by children detained in Unit 18 as "a pathetic attempt at grandstanding designed at shifting attention from the government's disastrous failures which lead to the tragic death of Cleveland Dodd".

ALS WA chief executive Wayne Nannup said the government's failure to safely look after incarcerated children in its care "has been catastrophic".

"To then demonise these children as occurred yesterday in Parliament reveals a government plunging to a new low," he said.

ALS WA noted that it has submitted more than 70 complaints about the conditions at Unit 18 and Banksia Hill Detention Centre including lockdowns; excessive uses of force; dirty and unhygienic cells; inadequate education, recreation, mental health support, medical treatment and access to legal advice; and inappropriate sexual conduct of staff.

"What we've seen is the dehumanizing of these young people and it's a violation of their human rights," said Mr Nannup.

"The treatment they've received is disgraceful and degrading and they're being treated as second class citizens. Unfortunately these kids have been placed in the 'too hard basket'. It's unacceptable and has already ended in a tragedy which could and should have been avoided.

"Instead of the scaremongering 'show and tell' tactics displayed by Mr. Papalia in parliament yesterday, this government needs to step up now, and we, like all fair-minded Australians, continue to call for the urgent shut down of Unit 18 at Casuarina's adult maximum security prison."