The Corrections Department has been found to have breached patient rights in two separate instances of poor care in prisons.
In reports released today, the public health watchdog found Auckland Prison provided poor care to a 30-year-old inmate following a tooth extraction in mid-2013.
Read the report into the case at Auckland Prison (PDF, 440KB)
In the second case, poor nursing care at Spring Hill Corrections Facility in Waikato between November 2012 and March 2013 meant a middle-aged inmate with complex health needs endured strong pain for four months before prison doctors were told he had cancer that had spread. This inmate later died.
Read the second report (PDF, 647KB)
Deputy health and disability commissioner Theo Baker said both cases were unacceptable, and legal action may follow over the tooth extraction case.
She said it was the first time any prison facility in this country has been investigated by the office and found to have breached patient rights.
Listen to RNZ health correspondent Karen Brown
Ms Baker said prison inmates were totally dependent on prison staff to meet their needs when they were ill.
She said, in relation to the man in his mid-50s at Spring Hill, it meant he could do little more than complain.
"If you're in pain you can't think, 'Well, I will go and see a different doctor'. I mean he can't even get to see a doctor unless the nursing staff enable that to happen.
"So he can't go and buy over-the-counter medications, go and see a doctor, go to ED or any of those things - he's entirely reliant on those staff, and that's why I found that Corrections as a whole breached his rights."
Ms Baker said she was very concerned about both of the complaints. She said she checked, and there had not been an investigation by her office before into prisons - let alone any which found that inmates' rights to good healthcare were breached.
"I felt it was important to recognise the rights of prisoners to the same standards of care as they would receive in the community and I was very concerned about the quality of care in both of these cases."
The Department of Corrections has accepted it did not provide the care it should have to the two ill prisoners.
Correction's national director of offender health, Bronwyn Donaldson, said the nurses involved were still employed, but all its nurses were under observation.
Ms Donaldson said, when the investigation began, a lot of nurses had to explain why there was not good documentation around care.
Listen to Corrections national director of offender health Bronwyn Donaldson respond to the reports
Prisons under scrutiny
The release of the two reports comes as the Corrections Inspectorate investigates a prisoner's death on 13 August at Mt Eden Prison.
The inspectorate has also announced investigations into allegations about organised fights, contraband, inmate injuries and the death of another prisoner in Northland in June.