Changerup crash information sought by police.

Major Crash Investigators are calling for witnesses after a 21-year-old man died in a Changerup crash January 15.

Just before 9am a 2004 Blue Holden Commodore sedan traveling west on the Collie - Changerup Road crossed to the wrong side of the road and struck a tree near the intersection of Marinoni Road.

The driver of the vehicle, a 19-year-old woman, was taken to Kojonup Hospital and transferred to Royal Perth Hospital shortly after.

A 21-year-old male passenger died at the scene while the other two passengers in their 20's were taken to Royal Perth Hospital via the RAC Rescue Helicopter.

Anyone with information or dash cam footage regarding the crash, or saw the Holden Commodore being driven prior to the crash, are asked to contact Crime Stoppers on 1800 333 000 or at www.crimestopperswa.com.au.