The private operator of Mount Eden jail says there was no extra monitoring of a prisoner, despite the serial escapee's history.
The Corrections Department has fined Serco New Zealand $150,000 over the breakout by Aaron Forden last October, and ordered the company to make a raft of changes.
Serco had been running Mount Eden jail for less than seven months when Forden scaled a wall and escaped. Forden is currently before the courts over the escape.
He had already escaped once before from Mt Eden, in 2008, when it was run by Corrections, using knotted sheets to get over a wall.
Last June he also escaped from a supposedly secure room in Whangarei District Court.
Serco New Zealand's managing director Paul Mahoney told Checkpoint there was no additional alert in relation to Forden.
He said Serco is considering extra monitoring for high risk prisoners, but would not say what other improvements have been made.
Corrections and Sercocarried out a joint review following the escape.
The department has refused to release the report to Radio New Zealand, saying it would put the security of the jail at risk, but two staff members were warned.
But in a summary it says 35 recommendations were made focusing on policies and procedures, contingency management, staff competency, training and culture and the security of the building.
The department says a number of these changes have already been implemented but a prison monitor will remain in place until all the recommendations are actioned.
A prison officers union, the Corrections Association, says Serco New Zealand is incompetent, and the Government should revoke its $300 million contract immediately.
The union says the breach to public safety is cause enough to revoke the six-year contract.
However, Mr Mahoney says he is confident there will not be another escape.
The department's report found staffing on the night of the escape was adequate and the building met standards. It said other noises helped mask the sound of Forden's escape.
Department chief executive Ray Smith says he is confident that Serco, which has had a chequered record overseas, is capable of running the prison effectively.
Mr Smith says the company has been very cooperative with the investigation, and is actioning the recommendations.