The rise is so steep that the backlog of deaths-in-custody inquests at the start of this year was the largest since 2000, when records of pending inquests began.

Forty-three people died in police, prison and immigration custody in 2013, the largest number since 1997, when there were 56 deaths in custody. It continues a five-year trend in which the average number of deaths has risen to 37 a year since 2009, up from 28 a year  during the previous five years.

Natural causes were the most common cause of death, a trend linked to an ageing prisoner population with high rates of chronic disease and mental illness. Eighteen deaths were from natural causes.

 

Hanging and vehicle accidents each caused seven deaths and jumps or falls caused six deaths. The remaining five fatalities were from drugs and alcohol, drowning, blood loss and homicide.

The surge in such deaths means many families must wait years to find out how and why their loved ones died.

National standards state that no family should have to wait more than two years for an inquest, says coronial law expert Chris Atmore from the Australian Inquest Alliance. "Well that's just a joke."

It is not unusual for inquests to conclude five years after the person has died. "And it can be up to seven [years]," Dr Atmore said.

"You think about the trauma the family's gone through with the death and then to have it prolonged for so long while they hope for some outcome that's meaningful, that just seems cruel to me."

Delays were "particularly long" when police actions have been called into question – a direct result of the conflict of interest posed by police investigating police, Dr Atmore said.

"In those circumstances there needs to be an independent process of investigation. Police do the investigating for the coroner … [and] are often the ones that drag the chain when it comes to putting the inquest brief together."

A spokesman for NSW Police said the state had the lowest death-in-custody record of any jurisdiction but did not provide figures to support the claim.

The NSW Coroner's Court has the highest case clearance rate of any state or territory, the latest Productivity Commission report shows. Coroner's records show NSW completed 75 inquests into deaths in custody between 2012 and 2013, compared with 55 in the previous two years.

Yet 66 inquests were still incomplete at the start of 2014, compared with 36 at the start of 2009. Several dated back to 2010.

A spokesperson from the NSW Coroner's Court said investigations had become "more detailed, time consuming and complex in recent years".

The family of Aboriginal man Mark Mason waited three years for the coroner to complete his investigation into why the 44-year-old was shot dead by police in 2010, after he crashed his car into theirs and fled the scene.

"[It was] pretty devastating," his sister Marcia Mason-Hoskins said.

"We had no understanding. The questions, the anger, the emotion, really set in during those years."

A former field officer with the Aboriginal Legal Service NSW/ACT, Mr Mason, a father of four, was   the prankster and peacemaker of the family, Mrs Mason-Hoskins said.

"He was a very humorous person, always put people at ease … He brought a lot of laughter into a lot of people's lives."

At the 2013 inquest into Mr Mason's death, Deputy State Coroner Hugh Dillon described the Gamilaroi man as "a good man who loved his family and who won the respect of those with whom he worked".

"But clearly, the Mark Mason who was known and loved to so many people was not the person who police met" the night he was fatally shot, Magistrate Dillon said. His investigation concluded that police had acted "correctly and justifiably" and that the officer responsible had killed Mr Mason in self-defence.

Mrs Mason-Hoskins says the inquest has only compounded the family's trauma, and they will hold a rally in Collarenebri this month – the fourth anniversary of Mr Mason's death – to call for his case to be re-examined.

The deepest injustice, she says, is that despite the years of waiting, the trauma and the doubt, the coroner had made no recommendations to prevent similar deaths in future.

"In what man's language is it OK that you take a life with nothing to happen from it?"

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