ACT Chief Minister Katy Gallagher.

ACT Chief Minister Katy Gallagher. Photo: Jay Cronan

Chief Minister Katy Gallagher has described a death in Canberra's jail as ''terribly tragic'' but says ''there is nothing to hide'' about the incident.

The Health Minister acknowledged on Friday that the mental health services at the Alexander Maconochie Centre were under pressure but said she believed they were working well and were among the ''best in the country''.

A 30-year-old inmate committed suicide in his cell in the prison's health centre on Tuesday night, just one month after authorities were warned he was at risk of self-harm. The government says guards checked his cell less than an hour before his body was found just before 7pm.

The Alexander Maconochie Centre.

The Alexander Maconochie Centre. Photo: Jay Cronan

It is still unclear why the inmate was locked in the prison's health centre, which is understood to be inappropriate for those at high risk of self-harm or suicide.

Fairfax Media revealed on Friday the prison was close to capacity on the night of the death.

Three hundred and nine inmates were in the 332-bed jail, with not all beds available for use due to strict restrictions governing the placement of prisoners. The government would not answer questions on Friday about why the inmate was being housed in the health centre instead of the specifically designed crisis support unit.

Corrections Minister Shane Rattenbury also declined to say whether the crisis unit was full on the night of the death.

''In light of ongoing investigations, I am reluctant to provide any further comment,'' he said.

A former prisoner, speaking anonymously, said he had ''no doubt'' the inmate would still be alive if he had been housed in the crisis support unit. The former prisoner spent over a month in the unit over two stints in 2010 and 2011 and has also spent time in the Hume health centre, where the inmate's body was found on Tuesday night.

He said the health centre was riddled with potential hanging points and was difficult to monitor.

During his time in the crisis support unit, the former prisoner said he saw several suicide attempts, which staff pounced on almost immediately.

He said it was nearly impossible for an inmate to take their own life in the unit.

The deceased inmate's case appeared before the ACT Magistrates Court briefly on Friday.

He had pleaded not guilty to allegations that he assaulted his girlfriend in Civic one night in early June. Prosecutors applied to have the charges abated, given the man was dead.

''It's terribly tragic and there is nothing to hide,'' Ms Gallagher said.

The Chief Minister said she was satisfied with the mental health services at the centre.

The government has set aside an extra $1 million over four years for forensic mental health services because of the high demand and workloads. The money is expected to pay for an extra consultant and an extra nurse.

Ms Gallagher said the government's view was that the ACT's forensic services were among the best in the country ''in terms of resourcing and what prisoners have access to'', despite the missing infrastructure of a designated secure mental health unit.

Fairfax Media revealed this week the completion date for a forensic unit has been pushed back more than a year to May 2017.

Ms Gallagher said it was her understanding that there were daily meetings about the placement of prisoners.

■ Support is available for anyone who may be distressed by phoning Lifeline 131 114; Mensline 1300 789 978; Kids Helpline 1800 551 800.