Adam Giles has defended comments he made in 2010 that, if given the job of corrections minister, he would put criminals in "a big concrete hole".

Mr Giles, who has spoken of his shock after this week's Four Corners report into the treatment of youth inmates, told the NT Parliament while in opposition in 2010 he "would love to be the corrections minister" — a position he now holds after stripping John Elferink of the portfolio yesterday.

During the 2010 sitting of parliament, Mr Giles had complained of the then-Labor government's "soft and flaccid approach of the treatment of prisoners in the Northern Territory", which he said was "having a detrimental effect on building the social fabric in our towns".

"It is not the portfolio I really aspire to but, if I was the prisons minister, I would build a big concrete hole and put all the bad criminals in there … 'Right, you are in the hole, you are not coming out. Start learning about it'," he said at the time.

"I understand there are rules which guide the prisons in Australia and the United Nations, and how we use basic human rights in the treatment of prisoners and so forth. I understand that.

"What I do not understand is how we are soft, flaccid, and incapable of punishing prisoners in our Corrections system."

Mr Giles went on to say he "might break every United Nations' convention on the rights of the prisoner but, 'get in the hole'".

Today, Mr Giles defended the 2010 comments in an interview with 1049 Mix FM.

"Labor's been very good at digging up my past comments and farming them around to the media and making the issue of child protection a political issue," he said.

At a press conference after his radio interview, Mr Giles said "five incidents" seen in the Four Corners story occurred under the watch of the previous Labor government.

"I have sought to change lots of things since being in government and I would like to think the prison system now is a lot better than four years ago."

Mr Giles said it was the NT who instigated the inquiry into youth detention.

"It was the Northern Territory Government's suggestion to have the royal commission … it is good to see the Prime Minister come on board and support that from a joint initiative," he said.

Asked if restraint chairs — such as the device in which Dylan Voller is seen strapped into — had been introduced before appropriate legislation had been enacted, Mr Giles said he would "like to take advice on that".

"The restraint chair, as I understand it, is part of the adult corrections system. I will have to take advice on that," he said.

Questioned on whether Mr Voller should be released from NT Corrections, Mr Giles said: "That's a matter for the courts. I don't get involved in the court process."

Yesterday, Mr Giles said he had been shocked by the Four Corners report of mistreatment of detainees and said he would look at options for a royal commission.

Soon after, Prime Minister Malcolm Turnbull announced he would initiate a royal commission in NT youth detention after being "appalled" by what he had seen.

Today, Mr Giles' administration came under fire from West Australian premier Colin Barnett, who said he did not believe the NT Government "competent to be running its youth justice system".

"I think there is a strong case for the Federal Government, with the support of other states, to take over the management of that until it is in good and proper shape," Mr Barnett said.