A man blamed for a collision with a police car caused by an officer says he is "over the moon" he has been cleared of any wrongdoing.
The Independent Police Conduct Authority (IPCA) has investigated the crash in Alexandra in July 2005, in which an unmarked police car driven by Senior Constable Neil Ford collided with a car driven by Shane Cribb.
Mr Ford and Constable Dairne Cassidy were convicted of attempting to pervert the course of justice after they tried to show the accident was caused by Mr Cribb, when it was actually Mr Ford's fault.
The IPCA found multiple failings by Southern District police in their investigation. The authority's report said police failed through a lack of adequate supervision and did not address the concerns of Mr Cribb in a timely manner.
However it said the situation was unlikely to be repeated due to a new code of conduct procedure being introduced.
Shane Cribb said he was sad he'd had to go through the court case when it should have been clear cut, but can now move on. "Over the moon at the moment, just good to have my name fully cleared," he said.
Mr Cribb's friend Stephen Potter, who took the case to the IPCA told Radio New Zealand's Checkpoint programme on Friday there needed to be a lot more independence in investigations.
District Commander Superintendent Andrew Coster said relationships with police were damaged and have had to be rebuilt. Mr Coster said it was a single incident and doubts the police would find another case as disappointing as what happened in 2005.