Claims are being made that mental health patients are more likely to get help in prison than in the public health system.
National secretary of health technicians' union, APEX, Dr Deborah Powell, says Corrections pays tens of thousands of dollars more to psychologists than District Health Boards.
She said that's leading to a shortage of qualified staff in the health sector, meaning patients are getting a raw deal.
"It is an absolute indictment on our health system that people have to present to Corrections and the justice system before they will get their health needs met," she said.
New Zealand's issues about mental health care have come under increasing scrutiny due to our high suicide rates.
The new government is planning to begin a review of the country's mental health services.