Former Mt Eden remand prison inmate Alex Littleton is suing Serco New Zealand for half a million dollars, claiming the private prison manager was derelict in its duty of care, enabling two assaults on him, one of which saw him pushed over a balcony breaking both of his legs.

The attack on Littleton was made public in 2015 by Labour Party corrections spokesman Kelvin Davis after the discovery of video footage showing organised fighting groups at Mt Eden Correctional Facility triggered an investigation into Serco's management of the remand prison which ultimately saw the multinational outsourcing company lose the contract.

Littleton's claim emerged in a July 7 ruling on whether the former inmate needed to provide security for costs and outlining the extent of discovery available in his suit. The judgment was recently published on the Ministry of Justice's website.

The former inmate is seeking exemplary damages totalling $500,000 from Serco, claiming the company was "negligent and in breach of duties of care it owed to him" by letting a "dominant culture of violence" take hold in the prison and providing inadequate supervision to prevent prisoner-on-prisoner violence.

Littleton also claims the unlock periods didn't allow easy supervision, that there wasn't adequate CCTV monitoring, that contraband searches and strategies to reduce violence were inadequate, that Serco didn't manage the influence of gangs in the prison, was ineffective in its management of his rehabilitation after the attacks and threatened him if he didn't let Serco discuss his affairs in the media.

Serco accepted it had some duties of care to prisoners when it was managing Mt Eden and some of the factual matters pleaded, but rejected it breached those duties.

"It says Mt Littleton's claimed injuries were not sustained as a result of organised fighting within the prison and that any breach of duty by it (which is denied) was not causative of any injury suffered by Mr Littleton," the judgment said. "It also says that Mr Littleton's allegations that it failed to provide adequate supervision or to manage the influence of gangs in the prison, even if made out, had no causative connection with the attacks on him."

Justice Edwin Wylie declined Serco's application for Littlewood to put up security for the company's court costs because it would stop the case from proceeding.

"Mr Littleton is a genuine plaintiff and in my view, access to the Courts in a case such as this is not lightly to be denied," the judge said. "An order for security which would have the effect of preventing the claim from being pursued should only be made after careful consideration, and only in a case in which the claim has little chance of success. That is not the case here."

The judge also ruled the majority of Littleton's application to discover documents was relevant, although he limited the breadth of access to incident reports and operating policies at the time of the attacks.

Justice Wylie said for Littleton's case to succeed he will need to show "Serco deliberately ran a consciously appreciated risk that he might be injured as a result of breaches of the duties of case it owed to him" and that while a report by the Department of Corrections' chief inspector found Serco management had been notified of organised fighting rings and that there was insufficient supervision, "the most reliable evidence of Serco's knowledge and of the risks it consciously ran is likely to come from its internal records."

An interlocutory hearing in chambers is scheduled in the High Court in Auckland today.

Serco has already repaid $8 million to Corrections after the Crown invoked its step-in clause to take back management of the Mt Eden facility halfway through a 10-year, $300m contract. The company sought to have the investigation report into its management rewritten through the High Court, but was rebuffed by Justice Karen Clark who called the criticisms "wholly unwarranted" of a fair investigation and error-free report.

The company still holds the management contract for the Wiri prison in South Auckland, and posted a loss of $10.5m on revenue of $52.1m in calendar 2016, compared to a loss of $11m on revenue of $64.1m a year earlier.