Major Crash officers are investigating a serious crash which occurred on the South Western Highway in Cookernup on Friday, September 2 about 9.50pm.
The crash involved three vehicles and happened when a white Toyota Hilux utility travelling northbound crossed onto the incorrect side of the road.
Here is collided with a Landrover Defender and Nissan Navara utility travelling in the opposite direction.
The passenger of the Nissan Navara, a 23-year-old man from Marangaroo, suffered life threatening injuries in the crash and was conveyed by the RAC Rescue helicopter to Royal Perth Hospital for medical treatment.
The driver of the Nissan Navara, a 26-year-old man from Marangaroo and the driver of the Toyota Hilux, a 20-year-old man from Boyup Brook, were seriously injured.
The driver and passenger in the Landrover Defender were not injured.
Major Crash investigators are seeking people who may have witnessed the crash and or seen any of the vehicles described driving in the Harvey or Cookernup areas prior to the crash.
Anyone with information is asked to call Crime Stoppers on 1800 333 000 or make a report online at crimestopperswa.com.au
