A motorcyclist is dead after a collision between his bike and a police car near Te Kauwhata in Waikato.
Paul Brown, 38, died after his Kawasaki road bike collided with a patrol car that was turning to chase a speeding vehicle.
Officers say the officer in the patrol car was performing a three-point turn at 4.15pm on Sunday when the motorbike came over the brow of a hill about 50m away and collided with the car.
The impact of the crash threw Mr Brown several metres, fatally injuring him.
Police say the speeding vehicle was doing 154 km/h, and the officer in the patrol car had switched on his emergency lights and siren.
The Bikers' Rights Organisation says police driving proceedures are putting motorcyclists at risk.
A police officer was convicted last year of dangerous driving after a collision with two motorcyclists while he was turning in the Buller Gorge.
The group's Wellington president, Brent Hutchison, says there needs to be a review of the policy used when a patrol car changes direction to begin a chase.
The group says Mr Brown was an experienced rider who will be badly missed by the motorcycling community. It says Mr Brown, who was from Te Kauwhata, had been riding motorcycles for years, and had raced competitively.
Waikato police say the officer has spent decades trying to save lives on New Zealand roads.
District road policing manager, Inspector Leo Tooman, says the officer is deeply distressed and off work.
Mr Tooman says it is unclear how far ahead the officer could see before turning.
He says it could take up to four weeks for crash experts to complete their investigation.
The CIB, the Independent Police Conduct Authority, the coroner and Serious Crash Unit are also investigating.