Dash cam footage has been released which shows the moment a 4x4 reversed back at speed into a police car in Bradford.
The footage shows another driver bumping up against the kerb as the silver 4x4 starts reversing through traffic in Otley Road on Monday.
It then smashes into the front of the police car, causing extensive damage.
West Yorkshire Police's Road Policing Unit is now appealing for information as efforts to trace the driver continue.
Anyone who can help the investigation is asked to call police on 101 or Crimestoppers in confidence on 0800 555 111.