The territory's top judge says it is ''unacceptable'' mentally ill people who pose a risk to themselves or others are kept in Canberra's jail or released into the community.

And Chief Justice Terence Higgins has slammed the Alexander Maconochie Centre's high remand population as ''shameful'' in a human rights jurisdiction.

The judge was echoing the concerns of Canberra criminologist David Biles's article for this newspaper this week, in which he called for an additional two judges.

In a speech at Friday's admissions ceremony for new lawyers, Chief Justice Higgins argued his case for both an extra judge and a secure forensic mental health facility.

Judges and magistrates have long called for such a facility, and after delays and cost blowouts the government allocated money for final design work in the last budget.

The Chief Justice warned the jail's crisis support unit, designed for short-term treatment, was ''in reality filling the role of a secure forensic mental health facility''.

The judge was reiterating the fears Human Rights Commissioner Helen Watchirs and Public Advocate Anita Phillips raised in July. ''Particularly in a human rights jurisdiction, it is not acceptable that people with a mental illness who are at risk of harming themselves and/or others are in jail or the community,'' Chief Justice Higgins said.

''Such people may be unsuitable for other mental health facilities due to the risks they pose. They require a facility that is designed to house and support them, providing the appropriate protection both to them and the wider community.''

A 2010 survey of Canberra inmates suggested about 70 per cent had mental health concerns, and the same proportion as having a psychiatric assessment during their lives.

Dr Biles's article highlighted the territory's high proportion of people on remand in the prison population. - almost 35 per cent, compared to a national average of almost 24 per cent. ''As Dr Biles pointed out, it is shameful that, in a jurisdiction that prides itself on having the first legislated human rights, we have the highest proportion of remandees in our prison population,'' the judge said. ''An increase in the number of judges would decrease the backlog of cases as well as provide greater opportunity for current judges to more effectively manage their reserved judgments.

''Together, this would result in a reduction in the waiting times for people remanded in custody.''