The Northern Territory Government has settled a class action brought on behalf of young Aboriginal detainees, who lawyers said were still being mistreated in the Territory's youth prisons despite the royal commission.

Key points: A class action on behalf of Aboriginal youth detainees allege mistreatment that breached the Racial Discrimination Act

A class action on behalf of Aboriginal youth detainees allege mistreatment that breached the Racial Discrimination Act The Chief Minister says the case comes "five years too late, against the wrong government"

The Chief Minister says the case comes "five years too late, against the wrong government" Both sides agree to confidential terms that have to be approved by the Federal Court

But it is not clear what—if anything—the Government has conceded or committed to do, with both sides agreeing to keep the settlement confidential.

The case, filed last August by the Northern Territory Legal Aid Commission, alleged young people were being subjected to excessive lockdowns in their cells without adequate access to fresh air, sunlight, exercise or education.

It also raised concerns about the poor handling of young people who were mentally unwell or at risk of self-harm.

Last year the Government rejected the lawyers' claim that the detainees' treatment amounted to a breach of the Racial Discrimination Act.

Chief Minister Michael Gunner said the lawsuit came "five years too late, against the wrong government".

But papers filed in the Federal Court show that "the parties have agreed on terms" to resolve the matter, pending the approval of a judge.

A key document filed with that notice cannot be inspected by anyone without the court's leave.

Attorney-General Natasha Fyles would not say whether the agreement was an admission of any fault.

"These are matters that are before the courts, we will allow [them] to run their course," she said.

Legal Aid declined to comment beyond a short statement confirming agreement had been reached and approval was pending.

"Legal Aid continues to visit children in detention and advocate for their wellbeing and to ensure they have positive opportunities to turn their lives around," the statement from director Susan Cox said.

"We will provide more information about the outcome of legal proceedings at the appropriate time."

Lawsuit sought to improve conditions or shut centres

The lawsuit did not make a claim for any financial compensation for the young people involved in the matter.

Instead the claimants asked the court to direct the Government to improve conditions inside the centres, or force them to be shut down.

They also wanted declarations from the court that the detainees' mistreatment had been unlawful.

The agreement was reached in mid-April, shortly after the Government passed laws that retrospectively eased restrictions on the use of force and isolation in the detention centres.

Two days after the confidential document was signed, the Territory Families department published a three-page Statement of Commitments setting out minimum standards for some of their work in the facilities.

It includes requirements around minimum hours of recreational and therapeutic activities, the content of annual refresher training for youth justice officers and coordination with Aboriginal health and legal groups.