Authorities made assurances that Steven Freeman, 25, would be kept safe after he was viciously bashed behind bars last year.

Freeman was targeted in his cell just hours after he first arrived at the Alexander Maconochie Centre, and after the remandee was placed with sentenced prisoners.

The attack almost killed Freeman. Prison guards provided first aid to keep him alive, and he was rushed to hospital, where he recovered, albeit with fears of a permanent brain injury.

After that bashing, Freeman's lawyers at the Aboriginal Legal Service had argued that he should be released, fearing further risks to his safety in the AMC.

There were fears about possible self-harm, or that he would again be targeted by fellow inmates.

But police and prison authorities made undertakings to the court that Freeman would be kept safe. Prison, it was said, was the "safest place" for him.

On Friday, however, Freeman died. The circumstances and cause of his death are still not clear.

The government has promised an independent inquiry and the death in custody will prompt a coronial inquest.

Little information had been given to the family and others about Freeman's death over the weekend.

Canberra's Aboriginal health service, Winnunga Nimmityjah, launched an appeal on Monday to raise money, food, and clothing donations for Freeman's family, who are still reeling in shock at the young man's death.

Winnunga's chief executive officer Julie Tongs said Canberra's Indigenous community was also in mourning.

"I think the wider Canberra community realises this is the young man who was nearly bashed to death within hours of entering prison some 13 months ago," Ms Tongs said.

"To now learn of his death inside that prison is horrendous."

The Aboriginal Legal Service, which tried to have Freeman released on bail repeatedly, said it was awaiting results of the prison's investigation.

"Aboriginal Legal Service (NSW/ACT) is very saddened to hear of the tragic loss of a young man's life in the Alexander Maconochie Centre," the service said in a brief statement.

"The loss of a young son is a devastating blow. Aboriginal Legal Service will be available to assist the 25-year-old's family."

Winnunga have asked for the family, including mother Narelle King, to be given privacy as they grieve.

At a bail hearing earlier this year, Ms King had warned the court that her son was not going to leave prison alive.

She gave evidence that she had received a phone call warning that her son would die in the AMC.

"I'm very fearful for my son's safety because I know he's not going to be walking out of there," she said last year.

A strict regime of effective home detention for Freeman while on bail was proposed as an alternative to him being held in custody.

But that was rejected, and Freeman deemed too high a risk of reoffending if released.

There were no reported disturbances at the time of Freeman's death, according to the government.

The discovery of his body was made after corrections staff were notified by another detainee who held concerns for his safety.

Justice Minister Shane Rattenbury has launched an independent inquiry into Freeman's death.

He said on Monday he was "deeply concerned" by the death, and that he was urging the inquiry be conducted straight away.

"We are currently in the process of identifying a suitable and available person to undertake the work and developing the terms of reference," he said.

"I am keen to get the inquiry under way as soon as possible and intend to announce details this week."

Ms Tongs said she hoped that process would be conducted swiftly, independently, and "truly impartially".

In the meantime, she called on the community to rally around Freeman's family.

"They have very little. Whatever help people can provide will help enormously," she said.

"Winnunga is in the process of setting up a donations account whereby people can donate electronically and 100 per cent of the donations/contributions will be passed on to Ms King."

Anyone who wishes to make a donation can drop it off at the Winnunga service on weekdays between 9am and 5pm, at 63 Boolimba Crescent, Narrabundah. Account details will be published on the Winnunga website on Tuesday.