Private prison operators Serco have failed to meet several key performance measures since taking over running the Mt Eden Corrections Facility, a Corrections Department report shows.
The report, released under the Official Information Act, shows two wrongful releases and one wrongful imprisonment in the eight months since the Mt Eden facility was handed to the British-based company.
It was fined $150,000 when Aaron Stephen Forden, a prisoner dubbed "Houdini", escaped earlier this year.
All of the incidents are listed as zero tolerance areas under Corrections Departments standards.
Corrections chief executive Ray Smith told Radio New Zealand Serco's failure to meet several performance measures was "less than we expect".