Oversight may have prevented Don Dale: AG

Attorney-General George Brandis has suggested the Don Dale Detention Centre abuse scandal may never have happened if better oversight measures were in place.

Mr Brandis reflected on the Northern Territory abuse saga after committing Australia to ratifying an optional international anti-torture treaty.

Ratification by the end of this year will see prisons, police watch-houses, juvenile justice and immigration detention centres across Australia monitored by independent inspectors.

A royal commission was established in the wake of footage showing boys being tear-gassed, spit-hooded and shackled in the NT's youth prison system was aired on national television last year.

Senator Brandis on Thursday considered what might have been different if the treaty was in place when the events at Don Dale emerged.

"It may well be that either they wouldn't have happened at all or they would have been arrested at a much earlier time," the attorney-general told reporters in Canberra.

"It is a concerning example of the fact that even Australia, which is a human rights respecting nation, is not perfect and problems of this kind can arise."

The government will work with states and territories to launch the network of inspectors after pledging to ratify the optional protocol to the convention against torture.

Australia signed the convention in 2009 but the government had never before committed to implementing it.

"The aim is not to shame; it is not to engage in an act of moral vanity," Senator Brandis said.

"It is to co-operate in a mutual endeavour to bring about a tangible improvement to the treatment of people in detention."

Australia needs a stronger, more independent system of safeguards around conditions in places of detention, says the Human Rights Law Centre.

"From the mistreatment of children at Don Dale to the death of (22-year-old Aboriginal woman) Ms Dhu in police custody, we've seen how things can go tragically wrong," said its executive director Hugh de Kretser.

"Implemented properly, (this treaty) will promote safe, well-managed places of detention. It will reduce mistreatment and risks of deaths in custody."

The new oversight measures will only apply to detention centres on Australian soil, not those immigration facilities on Manus Island or Nauru.

But all Australian-run places of detention - including offshore processing centres for asylum seekers and refugees - must be accessible to independent observers, says Amnesty International.

Nauru is party to the optional protocol to the convention against torture, but Papua New Guinea is not a signatory.