A motorbike rider is fighting for life after becoming trapped under a car in a horror multi-vehicle crash.
The crash involved three vehicles and happened on Tonkin Highway at the Great Eastern Highway off ramp in Bayswater about 5.40am on Monday.
The rider suffered life-threatening injuries after becoming trapped under the car.
Police, St John Ambulance and towing services responded to the crash, which caused major congestion and shut down the Tonkin Highway southbound entry ramp from Guildford Road.
Motorists are urged to exercise extreme caution and avoid the area.
If possible, consider exiting at Reid Highway or Morley Drive.
Police are requesting that people with information relating to the incident to contact Crime Stoppers by submitting a report online via www.crimestopperswa.com.au or calling 1800 333 000.