Please note: This story contains reference to someone who has died.

The family of an Aboriginal man who died in custody in 2015 gathered outside of New South Wales' Coroner's Court on Friday to demand an end to deaths in custody.

An inquest into the death of Wonnarua man Danny Whitton was launched on February 22 and will continue in May.

Whitton's sister Nikita House addressed the media outside of the courthouse on Friday.

"Our Danny Boy was a much-loved son, brother, father, nephew, cousin and uncle," she said.

"No one could ever forget Danny."

"It doesn't matter who he met, he always left his mark on them. He was known as the one with a cheeky mouth. He always had something smart to say."

House described her brother as a man who had a deep love for his family.

"The biggest thing he wanted for his daughter and family was to not make the same mistakes he did. He told us to never give up in life, to always follow our dreams and believe in ourselves," she said.

"He was a man who cared deeply about his family."

Nikita House speaking on behalf of her family at NSW Coroner's Court on Friday. Photo Supplied.

Whitton passed away at Royal Prince Alfred Hospital in Sydney after an accidental overdose which led to organ failure. He passed away on November 9, 2015 at just 25-years-old.

"Every day since then, we have dealt with so much pain and so many unanswered questions," said House.

The family noted the inquiry has helped them better understand the circumstances around Whitton's death.

"This week has helped to answer a few of those questions and fill in some blanks for our family," said House.

"It has been helpful to understand more about what happened to Danny, but it's caused anger and sadness too.

"We have learned that so much more care could have been offered to our Danny boy while he was in prison. He had the right to healthcare, just like every single person in custody.

"If that care had been given to Danny, we believe our boy would still be here with us today."

On behalf of her family House thanked the inmates that gave statements during the week of inquiry, along with the Aboriginal Legal Service and others.

"My brother Danny passed away much too young," she said.

"Five years later, our family still feels his loss every day. We do not want to see one more family have to go through this. Let's honour Danny's memory and make sure this never happens again.

"No more deaths in custody."

The inquest is set to continue on May 24.

By Rachael Knowles