Prison beatings happen in New Zealand almost daily and only "good luck" stands in the way of more deaths, the prison officer's union said today as fears of gang violence at Christchurch Men's Prison could continue to escalate.

Benton Marni Parata, 44, died after he was allegedly attacked by several inmates in his cell at Christchurch Men's Prison's high-security Rawhiti unit last Wednesday.

Today, three men - aged 20, 21 and 36 - were charged with his murder and are due to appear at Christchurch District Court next Wednesday.

"The police investigation team have been working closely with Corrections staff and the victim's family over the past nine days and will continue to do so. We still have ten police staff working on an ongoing investigation into this incident," Detective Senior Sergeant Mark Worner said.


Parata's alleged fatal beating has sparked several violent incidents in prison that has raised safety concerns by the Corrections Association.

One Christchurch prisoner, Terence Junior Whaanga, 25, of no fixed abode, appeared in court today charged with injuring with intent to cause grievous bodily harm another prisoner on Tuesday afternoon.

The man who was allegedly attacked was taken hospitalised but later returned to prison later that day.

Whaanga was remanded in custody without plea until April 9.

Gangs expert Dr Jarrod Gilbert, a spokesman for penal reform group Howard League, fears that revenge from Parata's death could "snowball" out of control.

Corrections Association industrial officer Beven Hanlon said the recent Christchurch violence highlights what is happening in prisons across the country.

"The beatings prisoners receive happen on an almost daily basis across the prison system," he said.

"It doesn't usually end with them being in a life critical condition, but that is more because of good luck than good management."

Mr Hanlon says prison officers are not equipped with the proper protection required to step in and break up fights.

If they had the tools provided to police officers, including stab-proof vests, batons, pepper spray, and Tasers, then they could do more to stop prison violence, Mr Hanlon said.

"Our job is to stop these things from happening and that's what we want to do. But we're just not given the protection to do our job," he said.

"When prisoners are fighting - and they do fight on a regular basis - there might be three staff and 40 or 50 prisoners wondering why we aren't stopping it. And the reason is that we can't stop it. It means other prisoners will step in and things can escalate to a major situation. Things can spiral out of control easy enough. "

Spring Hill Prison guard Jason Palmer, 33, died on May 16, 2010, a day after being punched by inmate Latu Kepu.

Mr Hanlon fears that the lessons learned from Mr Palmer's death "have already been forgotten".

Parata's suspected murder is just the eighth such case in the past two decades, according to Corrections.