South Australian police could have missed an opportunity to lay charges over the supply of heroin to a man who overdosed inside a doctor's surgery, a coroner has heard.
Lucas Adam Pike, 43, died after he and Athena Kyriacou were injected with the drug at her father's CBD medical practice in March 2016.
Opening an inquest into his death on Tuesday, counsel assisting the coroner Naomi Kereru said the pair bought $150 worth of heroin with a third man, Mark Campbell.
The court heard the three visited the Hindley St practice of Dr Jack Kerry, where Ms Kyriacou worked as a phlebotomist, and Mr Campbell injected the others in a pathology room.
According to Mr Campbell's statement, he left the room to inject himself but could not find a vein.
"He returned to the pathology room a short time later to find Ms Kyriacou slumped in a chair and Mr Pike standing upright, but turning blue," Mr Kereru said.
"Mr Pike said something to him and then collapsed to the ground."
The court heard Mr Campbell alerted Dr Kerry, who administered CPR to his daughter and directed him to work on Mr Pike.
Paramedics arrived a short time later and treated Mr Pike, but they were unable to revive him and he died at the scene.
A post-mortem examination revealed his cause of death to be heroin toxicity.
Ms Kereru said the police attended the scene and seized some personal items, but a report indicated they did not take drugs or syringes.
Later that night, officers searched a Kurralta Park home after they established a link between Mr Pike's death and the address.
They seized drugs, leading to the eventual conviction of a man on trafficking charges - but could not prove a connection between the heroin at the house and that which killed Mr Pike.
Ms Kereru said she was this week alerted that, contrary to the police report, there was a syringe seized from outside the pathology room.
State Coroner Mark Johns said had that syringe been tested, police may have have been able to establish a link to the deadly heroin supply.
"The heroin of the Kurralta Park address could be linked to not merely the supply of an illicit substance but to a death that resulted from that supply," he said.
The inquest will this week hear from Ms Kyriacou and Dr Kerry, but Mr Campbell has died in the years since the incident.