Herald on Sunday investigation prompts police watchdog’s inquiry.
The Independent Police Conduct Authority has launched an investigation into the "negligent" prosecution of a truck driver.
Last week, the Herald on Sunday revealed that police were ordered to pay tens of thousands of dollars to truck driver Graham Hohepa Anderson after he was blamed for a crash an off-duty cop caused.
Judge Gerard Winter dismissed careless driving charges saying the police "acted negligently" in prosecuting Anderson.
The judge also criticised the investigation and prosecution saying there was a perception it was "tarnished with bias", court documents show.
Now the IPCA has launched an investigation.
"The authority has asked police for further information on this incident and will consider its position once this information is received," a spokewoman said.
The charges against Anderson stemmed from a crash in October 2013. Anderson was carrying material in his truck to and from a construction site in Sandstone Rd, Whitford.
Off-duty officer Mark Hansen then "zoomed" past him accelerating to "110km/h if not slightly faster".
Hansen, who was in an "impatient mood", crossed the centre yellow line to pass the truck then clipped it as he tried to veer back on to the left side of the road.
When approached by the Herald on Sunday this week, Hansen refused to comment.
Police are already carrying out an in-house inquiry.
A police spokeswoman said the case had not been referred to the IPCA as it did not meet the criteria - but police had reviewed that decision after public interest sparked by the Herald on Sunday article.
The man who took the police case, Sergeant Mile Tusevljak, is now at the centre of the employment investigation.
Tusevljak served as an expert witness for the prosecution but the judge accused him of "particularly poor and unreasonable conduct" after failing to conduct basic investigations at the crash scene.
A spokeswoman for Counties Manukau Police said the investigation would "examine the actions of those employees involved in the crash investigation, prosecution decisions, supervisor actions for both the crash and prosecution actions, the investigation processes and practices".
Police hope to complete the review by mid-next month, but in the meantime the company Anderson worked for is pursuing a civil action against police to recover costs.
Judge Winter, who ordered police to pay 75 per cent of Anderson's $50,000 legal bills, urged the civil action. The company, Tebo, was left out of pocket after the truck was damaged in the crash and police impounded it for three weeks.
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