NT Chief Minister Adam Giles has sacked his Corrections Minister John Elferink in the wake of the damning ABC Four Corners report into the mistreatment of teenage prisoners, while alleging there has been a "culture of cover-up" within the Corrections system.

Key points: John Elferink remains as Mental Health Minister, Attorney-General

John Elferink remains as Mental Health Minister, Attorney-General Adam Giles alleges cover-up of video evidence

Adam Giles alleges cover-up of video evidence Staff seen in Four Corners report still in Corrections system

John Elferink, the minister responsible for young detainees in the Northern Territory, has been sacked in the wake of the damning ABC Four Corners report into the mistreatment of teenage prisoners.

At a press conference today, NT Chief Minister Adam Giles announced he had taken over the portfolios of Corrections and Justice from Mr Elferink.

"Can I start by saying that anybody who saw that footage on television last night on Four Corners would undoubtedly describe it as horrific footage. I sat and watched the footage and recognised horror through my eyes," Mr Giles said.

He said the footage aired in the Four Corners report had been withheld from him, Mr Elferink and "many officials in government" — with him only seeing it for the first time "on television last night".

"I think over time there has most certainly been a culture of cover-up within the Corrections system," he said.

"I think there's been a culture of cover-up going on for many a long year. The footage we saw last night [went] back to 2010 — and I predict this has gone on for a very long time."

He said his government had been "working very hard to try and fix many of those issues".

"What we're changing is a culture of an organisation within the youth detention system and I think we've come a long way in that time. That's not to discredit any of that terrible footage we saw on Four Corners last night. It was terrible footage but we're seeking to improve the system," Mr Giles said.

When asked if he personally was comfortable with children being strapped into restraint chairs, Mr Giles refused to answer definitively.

"We're going to have a look at that as part of the royal commission. We will have a review into that. I can't talk about individual cases," he said.

"There are kids who are trying to deliberately cause cranial issues by bashing their head against the wall.

"Prison officers need the ability to be able to de-escalate issues when children are not in … a calm environment within themselves and at all times those kids' wellbeing is being put at the best possible place.

"Having said that, there is certainly footage last night, particularly the footage dating back to 2010, 2012 and 2014 where I don't think the standards have been upheld."

Mr Giles said the Northern Territory community was "sick of youth crime … they have had a gutful".

"They've had a gutful of cars getting smashed up, houses getting broken into, people being assaulted. There's no doubt. And the majority of the community is saying let's lock these kids up," he said.

Sorry, this video has expired Four Corners: Royal commission announced

Some staff from footage still with corrections

The Acting Commissioner of Corrections Mark Payne, who took over in 2015, admitted some staff seen in the Four Corners report were still working with NT Corrections.

"A number of the staff, particularly those who have become the subject of previous investigations, a number of those staff members are no longer with us in the organisation. They've either been terminated in their employment or have chosen to resign," Mr Payne said.

"A number of staff members who may have been implicated to sustain charges, criminal or internal, remain with us.

"There were only two staff members identified in footage last night that still remain within the youth justice sphere."

Asked if he held any concerns for the welfare of youth detainees, Mr Payne said he did not.

"I have no concern and, in fact, I should remind the public that we have the Children's Commissioner and their staff come in to our facilities once a week," he said.

"We have representatives and our elders visiting program coming into the facility.

"We invite people in tours of the facility so as I stated previously, when I came into the organisation I found certainly a different place and its certainly a different place today in 2016 to what was identified in the footage last night."

Elferink office target of attack

Asked where the Mr Elferink was, Mr Giles answered: "I don't know."

"I imagine he's are probably in his office. I've advised John that I am assuming the Corrections responsibility immediately and that occurred five minutes before I walked into this office," he said.

Mr Giles said Mr Elferink would retain his other portfolios, including Health, Children and Families and Mental Health.

This morning, Mr Elferink's Darwin electoral office was the target of a vandal graffiti attack with police attending the scene.

Mr Elferink is yet to speak publicly since the Four Corners report, in which he is featured offering ABC journalist Caro Meldrum-Hanna a lift on his motorcycle to the Don Dale area where the so-called "riot" took place in 2014.

The ABC revealed the riot never happened and was concocted by prison authorities as an excuse for the use of tear-gassing of six boys.

The report has resulted in Prime Minister Malcolm Turnbull today announcing a royal commission into the Northern Territory's juvenile justice system.