One person has died while fleeing from police in Rotokawa, near Taupō.
The incident occurred early on Friday morning.
Police were carrying out a scene investigation at another fatal crash in the area when a vehicle overtook an unmarked police car on its way to the crash scene.
When police tried to stop the speeding car in order to protect those working at the scene, the car failed to stop and fled police.
Less than 30 seconds after the car began to flee it crashed through a fence, with one of the two people in the car dying in the accident, police said.
The other person in the car suffered sustained moderate injuries.
"This is an absolute tragedy and an outcome no one ever wants," said Bay of Plenty District Commander Superintendent Andy McGregor.
"We come to work every day to keep our community safe, and the staff involved have been deeply affected by this incident."
The crash will be investigated by both police and the Independent Police Conduct Authority.