David Dungay Jr died in Long Bay jail after being restrained by prison officers and repeatedly crying out "I can't breathe".
On Friday, the eighth anniversary of his death, his mother Leetona Dungay led a protest and vigil outside the Sydney prison, calling for justice.
"For all this time I've been fighting for justice for my son and, for all this time, the Australian government has refused to listen," she said.
In 2021, Ms Dungay submitted a complaint to the United Nations Human Rights Committee, arguing the NSW government failed to protect her son's right to life and that successive Australian governments have failed to implement all the recommendations from the 1991 Royal Commission Into Aboriginal Deaths in Custody.
Barrister Jennifer Robinson argued Ms Dungay's case at the UN.
She told AAP the Australian government has conceded it did violate Mr Dungay's right to life.
"That's a win for Leetona and what we're now asking the UN is to make a ruling about Australia's obligation to prosecute Black deaths in custody," Ms Robinson said.
And while nothing can bring her son back, Ms Dungay is hopeful her complaint to the UN will mean no more families have to endure the same pain.
"Aboriginal people are still dying in Australian prisons and hospitals, and there is no accountability," she said.
"By taking my complaint about David's death to the United Nations, I want to shine an international spotlight on systemic discrimination in Australia's prisons and healthcare systems.
"I want justice for David's death, and for all Aboriginal families who have lost loved ones to racism and discrimination in Australia's prisons and health system."
Mr Dungay was diabetic and had been diagnosed with psychiatric problems.
On the day he died, the 26-year-old had been eating biscuits in a cell.
When prison staff told him to stop and he didn't comply, five guards from the specialist immediate action team restrained him and handcuffed him to move him to another cell.
While being forcibly moved Mr Dungay repeated cried out "I can't breathe" and collapsed to the ground.
The guards pulled him back up and moved him to the new cell, where they restrained him face-down on the bed, with one officer kneeling on his back.
Mr Dungay kept repeating "I can't breathe" as a nurse injected him with a sedative.
He soon became unresponsive and attempts to resuscitate him were inadequate and failed.
An inquest in 2019 made recommendations regarding training and procedures of custodial and medical staff, and found the professional conduct of the nurse who injected Mr Dungay should be examined.
The coroner commented on systemic failures and found the way in which Mr Dungay was restrained contributed to his death.
But the coroner cleared custodial staff and rejected a submission from Mr Dungay's family that four Corrective Services NSW officers be referred for disciplinary proceedings.
"In Australia there have been more than 500 deaths since the 1991 royal commission into Aboriginal deaths in custody and only one per cent of those cases have been prosecuted, that's completely unacceptable," Ms Robinson said.
"In circumstances where we're seeing death after death of Aboriginal people in our prison system and in custody in this country, the Australian government needs to take a firm stance against and hold those responsible accountable."
Ashleigh Buckett, from law firm the National Justice Project, which represents Ms Dungay, said the Australian legal system has failed the Dungay family.
"Australia's concession before the United Nations is an important step towards accountability for David Dungay Jr's death, where our domestic legal system has failed," she said.
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