About 8pm on Saturday, May 13, detainee Mark Anthony O'Connor, 29, was reported to have collapsed suddenly and died in the jail.

Coroner Glenn Theakston released details of the man's autopsy late on Friday afternoon, saying it had identified no significant natural diseases or injuries which may have caused death.

The autopsy included toxicology results.

"Toxicological testing revealed a number of drugs and medications, including the presence of methamphetamine and buprenorphine that, in combination, may have resulted in Mr O'Connor's death," the coroner said.

"The significance of this opinion is still being investigated and further evidence will be sought."

Methamphetamine is an illicit drug also known as ice.

Buprenorphine, like methadone, is a synthetic drug used to treat opiate addiction by preventing withdrawal and lowering cravings.

Fairfax Media understands prison doctors can prescribe detainees Suboxone - which is a mix of buprenorphine and another drug naloxone - but only to those who cannot tolerate methadone.

Naloxone works to counter the effect of opiates.

The drug buprenorphine on its own is popular contraband among prisoners.

An inquest into the death of Steven Freeman, another inmate at the AMC who died of a drug overdose last year, heard these details from one of the prison doctors at hearings earlier this year.

Mr Theakston said on Friday Mr O'Connor's family had been notified of the developments. The coroner said he had approved the information's release given the significant public interest.

The investigation and coronial process is ongoing.

Meanwhile the Canberra Liberals sought to link justice minister Shane Rattenbury's advocacy for a needle exchange program in the prison to Mr O'Connor's death.

"Shane Rattenbury has been sending mixed messages for years about drugs in the AMC and now a young man has died in our prison," Liberal corrections spokeswoman Guilia Jones said.

"A young man who should have been going home to his family in 18 months will not be going home. This death is a failure of justice and the justice system."

But Mr Rattenbury said their stance was "irresponsible".

"The government is very clear we want to tackle drugs in the AMC and we've got a three-pronged approach to that," he said.

"One is to restrict the supply of drugs coming into the AMC and we've got a range of drug detection measures to prevent drugs getting in.

"We employ a range of security measures to prevent drugs getting into the jail including physical searches by corrections officers, passive alert detector dogs, we have metal detectors, x-ray scanners, we have more than 500 CCTV cameras through the jail and we work closely with ACT Policing to intercept drug transports so there is considerable effort being put in to stop drugs coming into the jail.

"The second response is to help people break their drug taking habits and there's a range of programs in the AMC to treat people's drug taking problems.

"The third leg of it is harm minimisation and that's where programs like a needle exchange program fit in.

"To reject the idea of harm minimisation as one of those three strands is simply irresponsible."

Mr Rattenbury also rejected any attempt to link Mr O'Connor's death to that of Steven Freeman, who died in AMC last year.

He said it was too early for the government to commit to an inquiry.

"I don't think it's appropriate to link this to the Steven Freeman death at this point in time, we don't have the Coronial results for either of those deaths so I can't draw that conclusion," Mr Rattenbury said.

"At this stage the coroner must still conduct the inquest so what's happened here is the Coroner has released the results of the toxicology report, so he's indicated the presence of those drugs but he's not made a finding into the cause of death so at this stage we will wait for the coroner to complete this process and see what recommendations the coroner makes and the government will decide how to respond."

An inquest and hearing into Mr O'Connor's death in custody will be held at a later date.