An inquest into the death of Indigenous inmate Steven Freeman has heard he was admitted to the prison methadone program two days before he died, despite no record he was ever using heroin.
The 25-year-old was discovered dead in his cell in the south wing at the Alexander Maconochie Centre about 11am on May 27, 2016.
The cause of Mr Freeman's death is relatively uncontroversial; an autopsy concluded it was aspiration pneumonia due to methadone toxicity.
What will be scrutinised in the inquest hearings that began on Monday is Mr Freeman's entry to the methadone program on May 25, 2016, and the quality of care and supervision afforded to him in the days following.
Mr Freeman received his first dose of methadone that day about 10.40am, and his second dose the following day, about 8.40am.
Senior Constable Gregory Ayton, who prepared a report for the coroner, told the court Mr Freeman's extensive health, court and prison records had revealed no suggestion the man, who had admitted using methamphetamine and cannabis, was using heroin.
While Mr Freeman once tested positive to the prescription drug Buprenorphine, Constable Ayton told the court his inquiries led him to conclude it was highly likely Mr Freeman was "opioid naive".
He also told the inquest how medical staff had reported inmates would use "all sorts of deceit" to get on the methadone program, and staff could not always be sure they hadn't "been fooled".
The officer said in the afternoon and evening of May 26, Mr Freeman had reportedly displayed a number of signs and symptoms listed in national guidelines as indicative of methadone overdose, including sedation, nodding off, an unsteady gait, slurred speech and snoring.
He had reportedly slept through lunch that day, Constable Ayton said.
One inmate, Ivan Djerke, told the inquest Mr Freeman was "smashed" after the second dose. Mr Freeman's cellmate said he was snoring deeply that night. Both inmates said Mr Freeman was not a heroin user.
Under questioning from Bernard Collaery, who is representing Mr Freeman's family, Constable Ayton said he had found no records that would indicate Mr Freeman was monitored in a health centre in the days following his entry to the program, as suggested by national guidelines.
The officer said he was not aware of any prison records that showed correctional staff had been instructed to look for signs of toxicity, or had available a record of who was on the methadone program.
Also aired in the inquest on Monday was the apparent ease with which inmates could access heroin, and methadone without it being prescribed.
Inmate Ivan Djerke told the court that of the 28 or so men in the unit at the time, he believed only a few weren't on methadone. Djerke said Mr Freeman had told him he was "getting a few drinks" of methadone off people in the prison. He said Mr Freeman had wanted to go on the methadone program to "do his time easy".
Djerke warned Mr Freeman against the idea.
"When you're on methadone, you're just sedated ... you escape reality, and that's why I told him it was a bad idea," Djerke said.
"I was disappointed with him that he got on the 'done.
"He's never used heroin ... and he shouldn't have been on [methadone]."
Djerke said after the second dose, Mr Freeman was "smashed".
It emerged in court that among the items found in cell 13 following Mr Freeman's death were two cordial bottles of clear liquid and one-and-a-half pills - possibly contraband - wrapped in plastic film.
Constable Ayton conceded under questioning by Philip Walker SC, who is representing the methadone prescribing doctor, that these items had not been the subject of testing. He also confirmed there had been no examination of a viscous liquid found on the cell shelf.
A large contingent of Mr Freeman's family and friends packed the public gallery and responded emotionally to the inquest's first day.
The hearing continues before Coroner Robert Cook.