A lobby group has carried out research which it says shows that prisons are breaching the rights of transgender inmates.
The equal justice project is headed by students at the Auckland University law faculty.
The research was conducted for lawyer Kelly Ellis, who wants the Department of Corrections to change its policies after seeing the mistreatment and sexual abuse that her transgender clients face.
The report says the department is breaching its own legislation by denying medical treatment for transgender prisoners who have gender dysphoria - a recognised medical condition.
Corrections Minister Anne Tolley said it's a complicated issue and the department is looking at its policies around the care of transgender prisoners.