Six prisoners who spent time in Don Dale Juvenile Detention Centre are suing the Northern Territory Government for incidents that occurred while in detention.

Key points: File for Dylan Voller seeks unspecified damages from the NT Government for injuries caused

File for Dylan Voller seeks unspecified damages from the NT Government for injuries caused Lawyer for Mr Voller criticised legislative changes introduced by former corrections minister

Lawyer for Mr Voller criticised legislative changes introduced by former corrections minister Mistreatment in detention "happened systematically", lawyer says

Six matters are before the NT Supreme Court Master in chambers today for case management, meaning the discussions are not held in open court.

However the file for Dylan Voller, who was shown on Four Corners last night being tear gassed, stripped naked and restrained inappropriately, seeks unspecified damages from the Government for injuries caused.

File for Dylan Voller seeks unspecified damages from the NT Government for injuries caused. ( Supplied )

Peter O'Brien, the lawyer for Mr Voller, now 18, and former prisoner Jake Roper, now 15, said there was a clear case of neglect in the Don Dale Juvenile Detention Centre.

"The most important thing about that is that when the footage was made available to the Government minister with the capacity to do something with it, nothing was done," Mr O'Brien said.

"There was no referral to the police at that time.

"There has been subsequently, but I'm sure that it's been the activity of the documentary-makers and producers on Four Corners, not the activity of the police themselves nor the activity of the minister or government responsible, to bring that to police attention."

Mr O'Brien also criticised legislative changes introduced by Attorney-General and outgoing corrections minister John Elferink to legalise certain types of force against youth inmates.

"This Attorney-General, when he found out about the abuse did do something: he legislated to condone it," he said.

"He legislated to allow 13-year-olds to be taken to prison, he legislated to allow this type of restraint, Abu Ghraib-type chair to be used legally.

"That to me is not only incompetent, it is despicable."

Abuse happened systematically: lawyer

Another file belonging to Ethan Astral seeks damages in relation to hurt, humiliation and injury caused by the Northern Territory's agents in the Don Dale Youth Correctional Centre.

The action comes a day after Four Corners aired disturbing images of young people being abused in prison.

But the revelations are not new — they were in a report tabled in the NT Parliament in September 2015.

At the time, the NT commissioner for corrections labelled the report inaccurate, "shallow" and "one-sided".

Derek James Tasker, a guard who was charged with aggravated assault, use of force against a detainee and procedure when youth "at risk" after an incident with Mr Voller, was found not guilty of all charges in 2014.

A Supreme Court appeal against that decision was also dismissed.

Mr O'Brien warned there would be further cases of abuse revealed in the future.

"It didn't only happen to my clients, it happened systematically," he said.

"If we only have the footage of the events that happened when they knew the cameras were operating, God knows what happened when the cameras weren't on."