New Zealand's only private prison operator, Serco, has been hit with another $150,000 fine for letting a second inmate escape.
Graham Hay, an inmate at Auckland's Mt Eden Prison, spent 30 minutes on the run after undergoing an eye procedure at the Greenlane Clinical Centre in early June.
An official report has found a non-standard pair of handcuffs was used to lock Hay to one of two guards escorting him to the appointment.
The larger-than-usual cuffs slipped off Hay's wrist, allowing him to escape before he was caught by a police dog.
The report says the incorrect handcuffs were used because prison officers had not properly checked the equipment beforehand.
None of Serco's staff have been sacked as a result, although managing director Paul Mahoney says it has issued written warnings to some staff. The company has been ordered to make operational changes.
Last year, Serco was fined $150,000 following the escape of inmate Aaron Forden.
The Corrections Department is in charge of overseeing Serco's $300 million contract with the New Zealand Government.
Deputy chief executive Christine Stevenson says Hay's escape was avoidable and the fine is warranted.