Six Auckland prison guards are fearing for their safety, after their private details were found in the cells of gang members last week.

LISTEN ABOVE: Mike Hosking talks to Corrections Association president Alan Whitley, about the privacy leaks. 

Documents containing the private details of guards, who were assaulted at the maximum security Auckland Prison at Paremoremo last October, were found in the cells of inmates.

One file was reportedly found in the cell of a Killer Beez gang member. Another was reportedly found in the cell of a Black Power member.

The guards suffered a range of injuries in the assault, including stab wounds inflicted with metal television brackets.

Corrections Association president Alan Whitley said the guards are concerned about the threats they could face, and what kind of protection they will receive.

"They're doing a difficult job in one of New Zealand's hardest prisons. They've been assaulted at work.

"They quite rightly want people to be held to account. They shouldn't be persecuted in the process."

In a statement, Waitemata Police District Commander Superintendent Tusha Penny said the documents were evidence in a forthcoming trial relating to the assaults.

"We are discussing appropriate security measures for the affected staff members however we will not discuss these measures publicly.

"We have expressed our deep regret to Corrections that this error has occurred."

Penny said Police became aware of the issue last week, and have launched an internal enquiry into what happened.

"The material was being disclosed as part of the routine prosecution process when the error has occurred.

"The disclosure has occurred as a result of human error. Police are working closely with Corrections on this matter."

The Corrections Association is seeking assurances the guards will be kept safe, and the incident will not happen again.

Whitley said it is not the first time the safety of the guards has been jeopardised, but it should be the last.

"I know the Police have apologised, and it's right that they apologise.

"Unfortunately this is not the only time this has happened, and we're seeking an assurance from them that it never happens again."