Not a single person interviewed for an inquiry into violence at Mt Eden Corrections Facility has confirmed the practice of "dropping" inmates from balconies, Serco says.
The company's lawyer Hayden Wilson told Wellington High Court today that the Chief Inspector of Prisons' draft report made no reference to the issue of dropping - in which new prisoners are allegedly thrown from a landing onto a concrete floor.
This was despite the fact that it was one of the key allegations against Serco, and contributed to the decision to launch an inquiry into organised violence at the prison.
"It was at at the forefront of the investigation," Mr Wilson said.
The issue of dropping was first raised by Labour MP Kelvin Davis.
Mr Davis claimed in Parliament that it was common at Mt Eden Corrections Facility, and may have led to the death of an inmate who was found to have a punctured lung after being transferred to another prison.
Mr Wilson said today that during his investigation, the chief inspector asked all 90 interview subjects whether dropping was taking place.
"All of them said, 'Not that I've seen'," Mr Wilson said.
He said the chief inspector's draft report was "entirely silent" on the issue.
It was only when Serco raised its absence from the draft report that the chief inspector amended it to note that no person had confirmed the practice of dropping.
Serco seeks new review on prison fights
Serco says a report into organised fighting at Mt Eden Corrections Facility includes anonymous, unverified allegations and it wants it to be rewritten.
The British-based company is today seeking a judicial review of the investigation by the Chief Inspector of Prisons in the Wellington High Court.
The chief inspector's report on Mt Eden prison was completed last year, but it has been held back because of Serco's legal challenge.
Mr Wilson told the court this morning that the investigation had departed from the terms of reference, contained errors of law, and had omitted relevant factors.
In a statement, the company said: "Serco claims that by relying on anonymous claims and allegations, which have not been verified or corroborated, the report is a breach of natural justice."
It was seeking an order that before the report was released, it was revised to "provide a fair and accurate account of the situation at Mt Eden".
The High Court hearing is set down for two days.
Mr Wilson said the judicial review was not an attempt by Serco to avoid criticism, and the company accepted most of the recommendations in the report.
However, the inquiry had expanded from its initial focus on organised fighting into a wider investigation of Serco's management of the prison.
Justice Karen Clark said the terms of reference allowed the chief inspector to investigate beyond organised fighting into general prison safety.
Mr Wilson said Serco accepted this, but that did not excuse the "wide-ranging detours" taken by the chief inspector.
He said the chief inspector also failed to verify some allegations, despite their "sensational" nature. These claims had ended up in the draft report completed in September.
Mr Wilson said the investigators had breached natural justice by failing to provide information about adverse findings, which would have allowed the company to respond.
In particular, Serco wanted interview notes taken by the chief inspector's team and in some cases the identity of the people making allegations.
If Serco knew who was making the allegations it could have provided greater detail, and also possibly identified whether any problems were isolated to a single prison unit.
On the rare occasions when these details were provided, Serco was able to respond in detail and the report was amended.