A former Otago prison doctor is calling for a review of the way prisoner health is managed.
Last week, Radio New Zealand revealed police are investigating the care of a prisoner before he died in February 2011 and reviewing another prisoner's suicide four months earlier.
Dr Wayne Cunningham worked in the new Otago Corrections facility for three years until 2010, just before the two deaths being investigated.
He says a lack of safe detoxification procedures and the priority given to security requirements meant it was a miracle no-one died while he was there.
Dr Cunningham says an inquiry should look at shifting prisoner care from the Department of Corrections to the Ministry of Health, as was done in Britain a decade ago.
But the department says it knows of no problem with its health service that needs fixing and the area already gets plenty of scrutiny.
Director Bronwyn Donaldson said the two deaths at Otago prison do not show a systemic failure.
Corrections Minister Anne Tolley says she has seen no evidence to contradict that Otago prison is doing a great job.
She says she won't be calling for a review.
A Wellington drug and alcohol counsellor says prisoners are enduring pharmalogical torture by being refused certain medications.
Roger Brooking told Morning Report that prison doctors are actively discouraged from prescribing certain drugs because of fears they will be traded - even though the prisoner would have to swallow the rationed medicine in front of staff.