Footage of an ACT Policing officer telling an Aboriginal teenager he "wouldn't have the guts" to "neck" himself has been condemned by the Territory's Indigenous children's commissioner, calling it a "deliberate incitement to an Aboriginal child to end his life".

First reported in The Canberra Times, the footage, played during a recent ACT Supreme Court sentencing hearing, shows an officer asking the teenager: "Right at this moment, are you thinking of necking yourself?"

When Jonathan, a pseudonym, replies "nah," the male watch house sergeant states: "Wouldn't have the guts to do it anyway."

Two of the other three police officers on duty can be seen briefly, faintly smiling after the comment towards the 17-year-old, who was also subject to the same senior officer appearing to mock him during his intake process for not having parents.

Justice Louise Taylor has referred the video to the ACT's Chief Police Officer, while footage of Jonathan being violently held down before being left alone in his cell while handcuffed for 45 minutes has already been sent to the ACT ombudsman.

On Monday, the ACT's Aboriginal and Torres Strait Islander Children and Young People Commissioner, Vanessa Turnbull-Roberts, said the "state inflicted trauma" of police's comments towards Jonathan would have been "compounded by the subsequent unnecessary use of force" before leaving him alone in his cell.

She added Jonathan would have known "not a single person" in the watch house would have "cared about whether he lived or died".

Having brought the incident to the attention of the ombudsman in December last year, the Bundjalung Widubul-Wiabul woman called for greater accountability around ACT Policing. The Canberra Times reported the complaint was still "being assessed" by the AFP, two months after it was first received.

Commissioner Turnbull-Roberts said that whilst the complaint was "apparently" forwarded to the AFP's internal investigative process, "it seems that nothing has yet been done in response to this abhorrent misconduct".

"This inaction shows how designed and broken this system is and how it is failing the ACT Aboriginal and Torres Strait Islander community," she said.

"What is even more horrific is the young person is a survivor of forcible removal, where during this time he was a child under the director general the police interrogation used against this young person by police is shameful. At every stage, policing and 'care and protection' bodies have failed to love and support this young person. Aboriginal lives matter."

During a recent Children's Court appearance, Jonothan said he "grew up in foster care".

"Stuff happened, which is f**ked, which shouldn't happen to a kid. But I'm not going to talk about that," he told the court, as reported by The Canberra Times.

In its original complaint, the Ombudman stated: "What might be construed as daring a young Aboriginal man to suicide while in custody is simply abhorrent and completely unacceptable."

The latest Closing the Gap data revealed the ACT has an average daily Indigenous incarceration rate of 28.6 per 10,000 children, above the national average of 26.1 per 10,000 and more than 14 times more than the rate for non-Indigenous children and young people.

Accounting for the small population of the Territory, this still saw an average of 4.2 Indigenous children and young people in detention in the ACT on an average day in 2023-24.

In her submission to the Senate Inquiry into youth incarceration, Commissioner Turnbull-Roberts called on the Commonwealth to make law amendments to ensure ACT Policing will be subject to discrimination and human rights laws.

"First Nations young people report high levels of racism and negative interactions in their dealings with our police force which is provided in the ACT by the Australian Federal Police," Commissioner Turnbull-Roberts in her submission.

ACT Police previously rejected calls by the ACT Human Rights Commission to agree to be subject to a human rights complaint process under the Territory's Human Rights Act.

The Commissioner called this "appalling," arguing cases like Jonathan's should be able to be brought before the ACT Human Rights Commission, "like complaints about any other ACT public authority".

She said the ACT "urgently" needed oversight of the police's treatment of vulnerable community members, noting they can't wait for the "inevitable tragedy" to due to "these discriminatory attitudes and behaviours".

"The commissioner's office does not want to see any blood, and with the current treatment towards Aboriginal children and young people, we are close to this and it's a national disgrace," Commissioner Turnbull-Roberts said.

"Aboriginal children and young people deserve better, deserve to live, thrive and exist on our lands and place. Abuse in watch houses, and/or anywhere on any person, is unacceptable"

The Canberra Times reported the AFP's Deputy Commissioner Scott Lee said he was aware of Jonathan's matter and the referral, and it had been under review before the referral by Justice Taylor.