The Department of Corrections is calling tenders for provision of care packages to treat inmates who are diagnosed with a mild to moderate mental illness.
From June the mental health status of each man entering person will be evaluated.
The Rethinking Crime and Punishment group says that with more than 50% of male inmates thought to have a mental illness of some degree, screening is a great start.
But it is very worried the treatment will not be appropriate and nowhere near the same standard that they could receive outside prison.
The group says knowing someone has an illness is one thing, doing something effective about it is something else.
Corrections says it is not aiming to select the cheapest treatment, but the most appropriate.