Hawke's Bay Regional Prison's assault rate is the second highestin the country because it is being run with "as few staff as possible," Bevan Hanlon says.
The prison's assault rate is worse than the controversially run Mt Eden Prison, although that facility is the subject of an inquiry following a failure to report serious assaults to the Corrections Department.
Radio New Zealand reported there were two state prisons with worse assault records than Mt Eden: the worst overall assault rate in the year to June was at Christchurch Women's Prison, with 37 assaults per 100 prisoners. The Hawke's Bay RegionalPrison was next, with a rate of 23.5 assaults.
Mt Eden Prison, which has come under the spotlight followingrevelations of fight clubs and violent attacks on inmates, came in third with a rate of 22.9.
The prison, run by private company Serco, although currentlyunder management from Corrections while investigations into the prison are ongoing, recorded 224 assaults by prisoners on each other or on guards.
The assaults ranged from minor spitting or pushing, to people requiring treatment in treatment and ongoing medical supervision.
Corrections Association president Bevan Hanlon, a formerHawke's Bay Regional Prison corrections officer of 17 years, said Mt Eden Prison's assault rate should be "taken with a grain of salt," because Serco had been allowed to report on its own performance to Corrections.
"We need to remember Mt Eden's going through a massive investigation because of under-reporting [of assaults]," he said.
Last month it was revealed a serious assault at Mt Eden Prison saw an inmate's arm broken at the elbow and spun like a windmill - a case which Serco failed to report to Corrections, even though its contract says serious assaults have to be raised.
Mr Hanlon was not surprised by Hawke's Bay Regional Prison's assault rate, which he believed was caused by several factors.
He said the prison had the highest density in the country of gang members, who were generally "violent, unpredictable people".
Cost-cutting decisions by management had also led to the prison being chronically under-staffed.
"They try and run the place with as few staff as possible.
"Surely these figures should mean there are some serious questions being asked of the prison director, as this is just getting worse under his watch. Levels of violence are a good indicator of the health of your prison."
The "unlock time" for prisoners, or the time during which they are allowed out of their cells, had also been reduced in order to cut staff shift times. He said keeping inmates locked up for longer made them more likely to behave violently.
In response, prison director George Massingham said Corrections had a zero tolerance policy toward violence.
The vast majority of assaults at Hawke's Bay Regional Prison were in the no-injury or non-serious categories.
"Staffing levels at Hawke's Bay Regional Prison are kept as close to the recommended staffing model as possible. Unlocktimes are no different than other prisons."
The department was in the third year of a staff safety plan, which aimed to reduce serious assaults in prisons, and included an anti-violence campaign and extended staff-training courses, Mr Massingham said.- additional reporting, NZME