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 the Department of Corrections even though its contract says serious assaults have to be raised.
A former inmate told the Herald convicted drug dealer Antony Gray's arm was snapped at the elbow. The inmate said the loose end was spun, causing Gray to scream in a way he believed would have been heard through the prison.
The 130kg Gray was a former boyfriend of Millie Elder-Holmes, reported in 2008 as supporting her then $1000-a-day P-habit.
• The Big Read: Life on the Inside
Last night, the Department of Corrections said the case had been referred to the Chief Inspector of Prisons as part of his inquiry into the Mt Eden Correctional Facility. Acting Northern Regional Commissioner Alastair Riach said: "The department did not receive any formal notification of an assault from Serco."
The contract between Corrections and Serco says "serious assault" must be reported - and beyond a certain level, Serco is docked about $35,000 each time an inmate winds up in hospital.
In a statement, Corrections Minister Peseta Sam Lotu-Iiga said it was important the Chief Inspector of Prisons be given the time to carry out his investigation and he expected the assault on Gray would be included.
The assault took place in 2014. A Court of Appeal judgment says: "While he was in custody, Mr Gray was attacked by a fellow inmate and sustained an injury to his elbow. [It] has subsequently required surgery."
The case has been seized on by Labour's Kelvin Davis as an example of a "don't write it down" prison culture, a claim which comes as an Official Information Act response reveals Mr Lotu-Iiga getting only verbal briefings on claims of serious violence inside Mt Eden.
Mr Davis had raised allegations of inmates being dropped from a landing to the floor below only to be told there were no records. "Now we know why. The easy way to avoid having these records is not to write them."
The Herald sought briefings to Mr Lotu-Iiga on media reports in December and February of illegal activity in prison and violence, along with claims of dropping at select committee in May. His office said he was "verbally updated".
The act compels ministers to supply even verbal information. A spokeswoman invited the Herald to go to the Ombudsman.