Scott Brideoake, the centre's general manager, this week gave evidence to the special commission of inquiry into ice, and was asked by counsel assisting, William de Mars, about the effects of the jail's regional location.

Mr Brideoake said the jail employed nurses and had other medial professionals like doctors and psychiatrists on a contract basis.

"We have a contracted psychiatrist that flies in from Sydney," he said.

"He flies in once a fortnight and provides us anywhere from eight to 12 hours.

"There's always challenges in a regional area like this to bring on relevant professional staff like psychologists, psychiatrists and even some of the nursing staff. It is sometimes difficult in a small town.

"We are lucky that we are about 50 kilometres from a large country town - Wagga. That does assist us a little bit."

David Shoebridge, a NSW Greens MLC and the party's justice spokesperson, has questioned whether that is enough time for a psychiatrist to spend at a correctional centre that houses almost 800 prisoners and is being expanded.

"There's lots of good evidence about the extent of mental illness in the prison population. There's some stats that are just deeply distressing," he said.

"The majority of people in prison have one, and sometimes multiple mental illnesses - illnesses that were pre-existing before they entered the prison population.

"The thought that there's a part-time psychiatrist on a fly-in, fly-out basis to deal with 800 inmates is distressing. It's woefully inadequate.

"These people often have complex stories of childhood trauma, chronic mental illness, addiction problems and addressing those mental health needs, you would think, is key to rehabilitation.

"Increasingly our prisons aren't focused on rehabilitation. They're a privatised system that warehouses people and deals very inadequately with often the mental health issues that are the cause, at least in part, of criminal behaviour."

Mr Shoebridge is also critical of this week's announced closure of four small regional prisons in NSW, which he described as the "harbinger of the Americanisation of prisons in NSW, where private mega-prisons will take the place of small, publicly-owned facilities".

"The loss of jobs in the regions will be significant, with correctional facilities often forming a key part of rural economies. We are calling on the government to guarantee transition plans for local workers," he said.

A spokesman for GEO, which operates the Junee Correction Centre, declined to comment.