Inspector of Custodial Services Neil McAllister also told Estimates his team, with just one full-time staff member, was "lean" and it was small enough they could "have team meetings in a telephone box".

The inspectorate was established in the wake of an inquiry into the 2016 death in custody of Steven Freeman, and Mr McAllister's team, which also has an $800,000 budget to hire contractors to help, is tasked with completing a whole-scale review of the prison at least every two years.

Mr McAllister said he had regularly visited the AMC since being appointed in November last year, and visited the ACT's court cells and would be conducting the complete review in early next year.

He told Estimates on Tuesday in similar roles in other states, he would have expected five or six staff, though he later said that was in the context of covering as many as 13 or 14 prisons.

Mr McAllister said he still believed he was adequately staffed and had enough resources to do the job of overseeing Canberra's adult prison.

He told Estimates he had brought in a contractor, who formerly worked for NSW custodial services, to complete the review of remand detainees, which he believed should be completed in a couple of months.

The review will look at the care and accommodation given to both male and female remand prisoners in the overflowing prison.

Mr McAllister said his concern was whether unsentenced prisoners were being afforded their human rights and were they being treated as "unconvicted" people.

He said a recent study of about 1000 in NSW had found up to 57 per cent of remandees did not ultimately serve a prison sentence, and it was likely up to half the ACT's remand prisoners could be in a similar situation.

The study, he said, also found up to 10 per cent of remanded prisoners were found not guilty or the charges were dropped.

While he said he could not go into detail about the investigation, it was "not uncommon" for remand detainees and convicted prisoners to mix together in regional prisons, though metropolitan cities usually had separate centres.

He said there was a "general human rights perspective" that sentenced and remanded detainees not be held together, and that at the prison, that was not currently possible.

"It's not unique to AMC but the fact there's unconvicted persons being held with convicted prisons, I wouldn't say it's a matter of concern, but it is a matter that requires me to ensure they are being properly cared for and properly managed," he said.

The AMC was much-promoted before it opened as being Australia's first human rights compliant prison, but has failed to live up to the promise as the prison population has swelled, leaving the government trying to deal with the fall-out.

While the review is expected to be completed in the next couple of months, any report by the inspector can stay confidential for up to six months longer, before it must be tabled in the Legislative Assembly.