Indigenous woman Rebecca Lyn Maher's death in custody three years ago could have been prevented if an ambulance had been called.
A NSW coroner's findings have determined that she would have survived if police had not breached their own policies.
Ms Maher, 36, was found dead in her holding cell at Maitland police station, located northwest of Newcastle, New South Wales, in July 2016.
An autopsy revealed she died from mixed drug toxicity after taking a combination of methadone and benzodiazepines leading to respiratory failure.
In delivering her findings, acting state coroner Teresa O'Sullivan said Ms Maher should have been searched and an ambulance called to assist her.
"Police should have concluded at that early stage that Rebecca was severely intoxicated," Ms O'Sullivan said.
"Rebecca was in a state where she should not have been kept in police detention, but instead taken to a hospital."
"If that had occurred, expert evidence suggests that Rebecca would have survived," she said.
She was detained by police for being intoxicated but had not been drinking. Two chemist pill bottles were found in one leg of her pants after her death.
Lyn Maher's mother Debbie Small, left, arrive at Newcastle Court for the inquest into her daughter's death. Source: AAP
The coroner said it was dangerous and inappropriate for police to think an intoxicated person could "sleep it off".
"I am troubled by the apparently prevailing attitude," she said.
"There is evidence to suggest that, from what could be seen on the CCTV monitor of Rebecca ... police had concerns about her manner of breathing."
The coroner said the six-hour delay to notify Ms Maher's mother of her daughter's death was "troubling", noting the information relayed to her was "misleading" and not done by a commissioned officer.
"I am concerned about the manner in which this was handled which was in breach of NSW Police Force requirements and was disrespectful," Ms O'Sullivan said.
The Wiradjuri woman was the first Indigenous person to die in a NSW police cell since a mandatory custody notification service was introduced almost two decades ago.
Acting Sergeant Gregory Hosie arrive at Newcastle Court for the inquest into the police custody death of Rebecca Lyn Maher. Source: AAP
A recommendation was made for the New South Wales police force to continue to review the circumstances of the death and use it as a training case to improve future responses.
Ms O'Sullivan acknowledged Ms Maher's family for their participation in the inquest.
"It is clear to me that Rebecca was a cherished and much loved member of her family, who continues to be dearly missed."
