VTNZ worker leaked police informant's details to Head Hunters gang

Vehicle Testing New Zealand (VTNZ) says it feels "let down" by a former employee who obtained the personal information of a police informant and passed it on to Head Hunters gang members.

The Privacy Commissioner earlier asked VTNZ to explain how the incident was allowed to happen, after Justice Matthew Palmer revealed what'd happened during his sentencing of six men convicted of the kidnapping and manslaughter of of 50-year-old Thai woman Jindarat Prutsiriporn on Monday.

The Head Hunters' 'Ghost Unit' first tried to kidnap Ms Prutsiriporn on February 15, 2016 - but became startled and abandoned the mission when someone watching on told police about a suspicious-looking group waiting outside her Auckland home. It was that person's details the VTNZ worker leaked to the gang.

A VTNZ spokesperson said "everyone in the organisation feels disappointed" by the incident, and said they would fully comply with the Privacy Commissioner like they did with police when the breach was first brought to their attention.

It said the employee's leak was "deliberate and conscious", and revealed the employee responsible had already left the company before its disciplinary process had been brought to a close.

Earlier on Tuesday, Privacy Commissioner John Edwards was made aware of the information and issued a statement saying he is "very concerned about the findings".

Mr Edwards said he would be requesting details from VTNZ about how the incident occurred, and asking for a rundown on their security processes and procedures.

VTNZ says it welcomes the involvement of the Privacy Commission, who it claims to already be in contact with - and said it was open to suggestions as to how to improve its systems and processes.

The breach came to light when, in his summary on Monday, Justice Matthew Palmer explained that a VTNZ worker - who had access to the company database - had handed over the informant's personal details to a member of the Head Hunters' Ghost Unit.

His comments come a day after the six men were sentenced to jail for the part they played in Ms Prutsiriporn's death. Five others pleaded guilty earlier in the legal process.

Ms Prutsiriporn was lured out of her home by the Ghost Unit on February 29, 2016 under the guise of a drug deal - and over the next 22 hours, she was tied, tortured, beaten and moved around several properties.

While she was being taken to another property, Ms Prutsiriporn managed to free herself from the boot using a steel kitchen knife, suffering serious head injuries in the process.

She died from her injuries two days later.