The family of David Dungay Jr has delivered an open letter to the NSW Parliament calling for the establishment of an independent body to investigate deaths in custody, and for those responsible for the death of Mr Dungay to be held accountable.
The Dunghutti man's mother, Leetona Dungay, said she has been fighting too long to secure justice for her son's death.
"Five years is a very long time for a mother to wait for justice," she said.
David Dungay Jr died in Long Bay Jail Hospital in 2015 when his cell was stormed by prison guards.
Ms Dungay said her son did not deserve to die in the manner he did.
"On the day he died my son was alone in his cell, eating a packet of biscuits, but the prison guards stormed his cell to take them off him," she said.
"Ten minutes later, he was dead. My son was held down by six prison guards and cried out 12 times, 'I can't breathe'.
"My son died over a packet of rice biscuits. He had so much life to live and should still be alive today."
'Peace, Justice, Accountability'
Ms Dungay said she wanted to see "a proper investigation" of her son's death and called on the NSW government to ensure that an investigation was undertaken.
"I'm here today to call on the government to give me and my family some peace," she said.
"I am here today to call on the government to give me and my family some justice.
"I am here today to call on the government to properly investigate my son's death and hold those responsible to be accountable for their actions at the time of my son's death."
More than 250 legal professionals, First Nations-led organisations, parliamentarians and other families who have lost loved ones in custody signed the open letter, which was delivered to NSW Parliament on Tuesday.
NSW/ACT Aboriginal Legal Service CEO, Karly Warner, said the calls in the letter stem from the "consistent failure from the legal processes" to deliver justice for families who have lost loved ones in custody.
"The Dungay family are sorely disappointed in the coroner's decision that failed to consider the criminal culpability of corrections officers," she said.
"Their disappointment has been compounded by a continued refusal by the NSW DPP and WorkSafe NSW to investigate the case."
National Justice Project director, George Newhouse, said a further 115,000 people have signed a petition demanding justice for Mr Dungay and his family.
"They've been waiting five years," he said.
"David died in December 2015 and although the coroner made findings that there was absolutely no need for David to be violently subdued inside Long Bay Prison Hospital on that fateful day, there has been no action, no accountability."
The open letter was received by Greens MP David Shoebridge on behalf of the NSW Parliamentary Inquiry into First Nations Deaths in Custody.
Mr Shoebridge will also deliver the letter to the NSW Premier Gladys Berejilkian and Attorney-General Mark Speakman.
"This is one of the moments where the Premier, the Attorney-General and the Parliament are going to be held to account," Mr Shoebridge said.
"Held to account by a family who have the backing of some of the most credible lawyers in the country to say David Dungay deserves justice."