If conditions don't improve at Waikeria Prison there could be a repeat of the Springhill riots, People Against Prisons Aotearoa says.
Waikeria Prison Photo: NZ Corrections Department
Independent inspectors who spent a week at the Waikato prison last year identified 42 issues including damp, dark cells where prisoners were sometimes locked away for up to 26 hours at a time.
Parts of the prison are so old and run-down that in 2012 four out of the nine high-risk wings were closed as they were considered no longer fit for purpose.
Further closures planned for 2015 were cancelled because of the rapidly rising number of inmates.
Corrections said it has fixed 30 of the issues and is making progress on the others including filling staff vacancies.
People Against Prisons Aotearoa spokesperson Emily Rakete said the report was yet another nail in the coffin for the prison and showed it was not fit for people to live in.
"Even setting aside the massive health risk that Corrections is willing to put these people in - Corrections has said the prison is old and deteriorated and things have got bad over the past few years - but people who were in there 10 years ago were complaining about how bad it is."
Prisoners told inspectors there were frequent violent assaults, mainly as a result of gang tensions but also because of boredom.
Standover tactics were common, especially to get another inmate's nicotine replacement patches.
Ms Rakete said Corrections was not learning from previous mistakes, which could lead to trouble.
"Conditions in Waikeria Prison right now almost exactly mirror the conditions in Springhill just before the riots and when Corrections investigated that riot it found it was caused by having extremely long periods of lock up."
More than 20 prisoners went on a rampage in June 2013 at Springhill Prison, destroying property and starting fires.
Record high prison numbers took the last government by surprise and National Party ministers proposed building a new prison at Waikeria at a cost of $1 billion.
Corrections minister Kelvin Davis is yet to make a decision on whether the new prison will go ahead.
In a statement Mr Davis agreed with the inspectorate that Waikeria's high security wing was not fit for purpose.
He said the government was considering its options.