A police officer had to be taken to hospital by ambulance in Christchurch on Saturday night after being injured while trying to stop a police vehicle from being stolen.
An eyewitness said he was dragged underneath the vehicle.
Police say the officer was later discharged from hospital after being treated for injuries described as minor to moderate.
The incident happened at a drink drive checkpoint on Buchanans Rd near Hornby at 11.30 pm.
It's understood two men were stopped at a police checkpoint and one of them somehow got into an unmarked police car.
The stolen vehicle was later found in a hotel car park, near the Riccarton racecourse.
The dumping of the vehicle was witnessed by a Westport woman at the hotel.
Leanne Aldridge, who is holidaying in Christchurch, says police cars turned up moments later in pursuit of the man who took off over a fence.