Corrections Minister Anne Tolley is resisting calls for private prison operator Serco to be stripped of its contract after it received another hefty fine for letting an inmate escape.
The British-based company has been running Auckland's Mt Eden Corrections Facility for a year and has twice been fined $150,000 for letting two inmates escape.
An official report on the latest breakout found that loose handcuffs led to Graham Hay spending 30 minutes on the run after a medical appointment in June this year.
Last year, inmate Aaron Forden escaped.
Mrs Tolley says the company has made a lot of mistakes and is not satisfied with its performance.
However she says she retains confidence in Serco, saying it is showing huge signs of improvement, and she is expecting a much better performance in its second year.
A union representing prison officers says Serco is not up to the job and the contract should be cancelled.