David Hill, Mr Dungay's father, and his family have attended every day of the inquest so far.
Speaking for the first time to NITV News, Mr Hill said the death in custody of David Junior, as he is affectionately called, had destroyed his life.
“Every day has been a struggle,” he said.
It’s been an exhausting week for all at Sydney’s Downing Centre, where witnesses are taking the stand, and evidence is being shown, in an attempt to understand what happened in the Long Bay Hospital the day Mr Dungay was killed.
Family is 'not coping'
Mr Hill said the hardest part so far was having to view the CCTV footage showing the harrowing moments leading up to his son's death in December 2015.
The court was played footage showing Mr Dungay spitting blood as he is transferred to the second cell while handcuffed and the injected with the sedative midazolam.
He is restrained by at least five IAT officers in the "prone" position. While facedown, he repeatedly screams, "I can't breathe!".
Mr Dungay became unresponsive, went "limp" and vomited, and could not be resuscitated, the court found.
Mr Hill explained it was his decision to only release half of the video to the court, leaving out the failed resuscitation process. He said it was simply too traumatic for his family.
His wife Kylie Hill said the footage, which has now garnered thousands of views online, has been incredibly hard for their extended family to see.
“We’ve got a lot of family back home that are not coping,” she said.
“David is one of 11 kids, so all of his brothers and sisters had to see it.”
One of the major findings so far in the inquest was that five of the six officers responding had no training or knowledge of positional asphyixia, the cause of Mr Dungay's death.
Prison procedures 'need to change'
Mr Hill and his family are now urging the New South Wales, and Australian government to rethink current prison procedures.
They say the lack of knowledge and culturally appropriate procedures in the prison and mental hospital systems is what is contributing to black deaths in custody.
"They don't follow procedures. They can't do this to us anymore,” Ms Hill said.
“They’ve got to stop these deaths in custody. They need to change policies and procedures across every state. “
Mr Dungay's aunt, Lisa Graham, told NITV News the family is not only looking for justice, but also want to spur a serious discussion about improving services for Indigenous people in custody.
"There is not enough Aboriginal liaison officers in the prisons or the mental hospitals, in Long Bay, or anywhere,” she said.
“We need more diversionary centres put up. We need more for our mob.”
One advocate supporting the Hill and Dungay families at the inquest is Ken Georgetown, the CEO of Queensland organisation Murri Watch, an organisation that runs jail programs in Brisbane, Mackay, Townsville and Palm Island aimed at reducing self-harm and deaths in custody.
Ms Graham believes if more organisations like Murri Watch existed in New South Wales and ran programs in Long Bay, the outcome for Mr Dungay might have been different.
The inquest continues.