On Friday, the eighth anniversary of his death, David's mother, Leetona Dungay will lead a protest and vigil outside the prison, calling for some kind of justice.
"He loved playing football - he liked sports - and he loved his elders, he was a happy go lucky person," she told AAP.
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 Corrections staff told him to stop and he didnt' comply, five prison 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 physically 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 became unresponsive soon after and attempts to resuscitate him were inadequate and failed.
A coronial inquest in 2019 made a series of recommendations regarding training and procedures of both custodial and medical staff and found that the professional conduct of the nurse who injected Mr Dungay should be examined.
David Dungay's mother Leetona Dungay has complained to the United Nations about his treatment. (Dan Himbrechts/AAP PHOTOS)
The coroner made a number of comments regarding systemic failures and found that 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 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.
"Governments are not listening," she said.
"No-one is going to be accountable and responsible or is going to be prosecuted so the only avenue we have is the Human Rights Committee from the United Nations."
Ms Dungay said she hopes the protest shines an international spotlight on systemic discrimination in Australia's prisons and healthcare systems and brings attention to all the people who have died in custody.
"We want to ask these guards and the government 'how do you still eat biscuits? Can you eat a pudding and all of that for Christmas, knowing you've killed a man in custody just days after Christmas?" she said.
Ms Dungay is being supported by human rights law firm the National Justice Project and top international human rights barrister Jen Robinson, who is expected to address Friday's rally.
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