The use of a restraint chair and spit hood on a 17-year-old in the Northern Territory's juvenile justice system has been described by the National Children's Commissioner as archaic, prompting her to call for greater transparency in all juvenile detention centres in Australia.

Commissioner Megan Mitchell said "tying a child to a chair and putting a hood over their head" taught children in juvenile detention that abusing people who were powerless "was normal".

Key points: Dylan Voller was a 17-year-old juvenile prisoner at the time of the restraint in March 2015

Dylan Voller was a 17-year-old juvenile prisoner at the time of the restraint in March 2015 He was strapped into a restraint chair by the ankles, waist, shoulders and arms

He was strapped into a restraint chair by the ankles, waist, shoulders and arms A fabric spit hood was placed over his head

A fabric spit hood was placed over his head He remained in both restraints under the watch of Corrections staff for 1 hour and 50 minutes

He remained in both restraints under the watch of Corrections staff for 1 hour and 50 minutes Restraint chairs are not used on juveniles in Australia outside the Northern Territory

"A child has a right to be treated with dignity and respect, no matter what he has done - and tying a child to a chair and putting a hood over their head is not the way to learn to respect others and to build trust in authority", Ms Mitchell said.

"It was very confronting to read about this teenager treated in this way.

"In my experience this is highly unusual and not normally the kind of tactic employed to restrain juveniles in detention centres in Australia."

The ABC revealed on Thursday that Dylan Voller was strapped to a restraint chair, similar to those used in Guantanamo Bay, by his ankles, shins, shoulders and waist.

He also had a spit hood placed over his head for almost two hours while he was in the care of NT Corrections in March this year.

The actions were sanctioned by the then commissioner of correctional services, Ken Middlebrook, who said the measures were taken for the safety of the detainee and staff.

Voller moved from Alice Springs to adult prison

Dylan Voller was restrained in a chair in March this year ( Supplied )

On the night the restraints were applied, Voller had been moved from the youth detention centre in Alice Springs to the adult prison where he could be more closely monitored by staff.

A departmental incident report confirmed Voller had threatened to self-harm prior to being placed in the chair.

"Prisoner Voller commenced to make threats of self-harm by saying that he would break his hand and break bones so that he would have to go to hospital," the report said.

NT Minister for Corrections John Elferink has told the ABC that restraint chairs were used on juveniles in the Northern Territory "as often as they have to be".

He responded to questions about the restraint of Dylan by saying juvenile detention centres and prisons "aren't necessarily pleasant places".

Restraint teaches children "the abuse of others is normal"

However, Ms Mitchell said: "I think such a response is not only at odds with our international obligations, under the convention of the rights of the child, but it's teaching children that the abuse of others, especially those less powerful, is normal and it's likely that it's also further traumatising an already damaged individual",

"Of course there are times when restraint is required for that individual's good or for that of others, and without knowing the details of the incident, there are much more sophisticated and less archaic ways of de-escalating a situation.

"I certainly think in most modern juvenile justice systems and you can see them in place all around the country - that these kinds of activities don't occur."

The Northern Territory is the only jurisdiction in Australia that allows the use of restraint chairs on juveniles.

Spit hoods are used on juveniles in South Australia, Western Australia and the NT to protect staff from being spat on.

The Children's Commissioner said there appeared to be a pattern emerging from the NT juvenile justice system "that reveals a somewhat kind of archaic culture towards children in these situations and I do think that things like behavioural management policies, staff skills and the culture in general are likely to need an overhaul".

Two separate reviews of the NT juvenile corrections system have been conducted in 2015; one by NSW corrections specialist Michael Vita and another by the NT Children's Commissioner Colleen Gwynne.

Both centred on the tear gassing of juveniles during a serious disturbance at the Don Dale Youth Detention Centre in 2014.

Breakouts and mistreatment of detainees prompted third review

The youth justice system in the NT has seen a spate of breakouts and allegations of mistreatment of detainees.

A total of 22 youths have broken out of youth detention centres in Darwin and Alice Springs in the last 18 months, with two young men breaking back in to Don Dale in dramatic fashion in July by driving a car through the centre's front doors.

Ms Mitchell has commended the NT Government for instigating a fresh review into youth detention in the Territory following the resignation of the head of corrections, Ken Middlebrook this week.

It will be the third review in 12 months.

Ms Mitchell said if Federal, State and Territory governments agreed to ratify the optional protocol attached to the convention against torture and other inhumane and degrading treatment it would trigger "a national monitoring mechanism for juvenile and other secure facilities and help to drive consistency and transparency" in the treatment of detained juveniles.

"Many of these children as we know, in fact most of these children are from very difficult backgrounds characterised by violence, abuse, substance abuse, a whole complex array of issues and so they're highly vulnerable," Ms Mitchell said.

"There is however a problem of transparency of all the systems around the country - and I am very hopeful that all the governments including the federal government will take steps to make sure that happens and in doing so make sure there is better oversight of these systems for very vulnerable young people," she said.