The NT Corrections Commissioner has urged prison staff to reconsider wearing their uniform while off-duty following a string of threats from the public following the Four Corners report into youth detention.

On Monday Four Corners aired shocking imagery of children in NT youth detention being abused at the hands of Corrections staff, including the tear-gassing of six teenagers in solitary confinement and a teenager being repeatedly abused and stripped.

The footage sparked widespread condemnation and sparked a royal commission into the Northern Territory's youth detention regime.

In an email to staff on Tuesday evening, Corrections Commissioner Mark Payne said that a number of staff members had received abusive and threatening messages from the public.

"I ask all staff to ensure that particularised threats of harm to any of our employees or damage to our facilities, vehicles or property is immediately reported to your local management team to ensure that a report is made to the Northern Territory Police," the email said.

The Commissioner also urged staff to reconsider wearing their uniforms when not at work.

"I ask that you also consider, at least over the next few days, the wearing of the NTDCS uniform when off-duty, such as shopping on the way home from work," the email said.

He said the "potential risk of harm to staff in these types of situations remains unlikely, avoidance where possible is preferable course of action and further reduces any likelihood of a situation developing".

Commissioner Payne said the "events and revelations of the past 24 hours" had caused a "difficult and challenging time for all of our people, and in particular those of us who have or are working in our Youth Detention Centres".

"I would like to personally thank all of our staff for the professional and resilient manner that has been shown in the managing the public criticism of our agency," he said.

"I am aware that some critics have taken to social and other forms of electronic messaging to post views that are quite distressing.

"I ask all staff to maintain their professionalism and to refrain from entering into public dialogue in respect of this commentary."

Sorry, this video has expired Four Corners: Shocking vision of Dylan Voller being victimised in youth detention

Today, the ABC revealed one of the guards involved in the tear-gassing incident at the Don Dale Youth Detention Centre said a teenager had been put in a mechanical restraint chair on at least three occasions before the 2015 vision was filmed.

Dylan Voller has also told his lawyers he had been in the mechanical restraint chair several times, the first time in youth detention when he was as young as 11.

The video obtained by Four Corners of Dylan hooded and strapped to a mechanical restraint chair has sent shockwaves around the world.

It was broadcast as part of an investigation detailing the repeated assault and mistreatment of children in youth detention, culminating in the tear-gassing of six children in Darwin in 2014.

In a written response to Four Corners a Northern Territory Corrections Department spokesman said the restraint chair had been used on youth detainees "once" and that it was used "only at adult correctional centres".

The ABC first revealed the forcible restraint and stripping of a 13-year-old boy in NT youth detention in 2014.

Despite the revelation, the government backed the actions of the guards and went on to introduce restraint chairs, despite appeals from human rights advocates and legal justice bodies.