How police discovered 30,000 'falsely or erroneously' recorded breath tests

Photo: RNZ

A series of documents reveal how police discovered about 130 staff "falsely or erroneously" recording more than 30,000 breath tests and the fallout that resulted.

RNZ can now reveal that the investigations began after a new mapping feature identified a police officer recorded 11 breath tests over a five-minute period over a distance of 3.5km.

There was no recorded traffic stop, checkpoint operation or call for service logged by or assigned to that officer during that period.

Police then audited all breath testing that took place from 1 July 2024 using an algorithm that determined if a second test took place within 90 seconds of the first, whilst the distance between the two indicated a speed of more than 20 km/h.

It found more than 30,000 tests, with more than 80 per cent of the staff under investigation belonging to dedicated road policing roles. Some of the irregular breath tests were recorded against staff who were rostered off duty, indicating the devices were used by colleagues without changing the logins.

RNZ earlier revealed about 120 staff were under investigation throughout the country after 30,000 alcohol breath tests were "falsely or erroneously recorded".

The results were only discovered after police built a new algorithm to analyse the data, as the devices themselves could not distinguish between legitimate and illegitimate tests.

On Friday, following an Official Information Act request from RNZ, police released 150-pages of information in relation to the breath screening tests investigation.

Photo: Supplied / NZ Police

Anomaly identified

On August 18, the director of road policing, Superintendent Steve Greally, emailed Assistant Commissioner Mi