An investigation has found organised fight clubs occurred regularly at Mt Eden Prison.

LISTEN ABOVE: Labour MP Kelvin Davis spoke to Rachel Smalley

A judicial review published today says they occurred once a week during some months - with the Chief Inspector of Prisons finding there was pre-fight training and rehearsing

His report says the demeanour of both the fighters and prisoners in Youtube and CCTV footage shows they are totally unsurprised at what is taking place and seem to treat it as an ordinary part of life.

The Department's now clear to proceed with its report after Serco lost a High Court case where it had sought to have the report rewritten.

While the report itself has not yet been released, the High Court judgement contains excerpts which state fights were planned and practiced for and the injuries sustained could be serious.

The report also found it was likely some prisoners were denied the right to call a lawyer for significant periods of time - and prisoners had been served food contaminated by animals.

The company had raised issues with process and also wanted a right of reply to anonymous information given by witnesses - however the Court's ruled the investigation was fair and the report is without error.

Labour MP Kelvin Davis now wants to see the report released immediately.

"Sunlight's the best disinfectant. I think the public has a right to see just how bad things were. Everything that we've been saying through last year as I'm sure it will be proven to be the truth.

"The High Court has come out with this judgement and said, look you're arguments are wrong and the process that was followed was a good process. I mean it's basically exposed Serco to show that they were just totally failing."

A spokesperson for Corrections Minister Judith Collins says Corrections is working through process for timing of, and in what form, the report will be released, to ensure any security and privacy issues are managed.

The Minister is therefore unable to comment at this time.