Goldfields police are asking for any assistance following a fatal crash overnight.
Local authorities attended a car accident at 7:50pm last night at the intersection of Thomson and Burt Streets in Boulder.
Several people were injured in the crash, while one of the men died a short time later.
Detectives from the major crash squad, including homicide squad and internal affairs will investigate the circumstances of the death.
The incident is being treated as a death in custody.
If you have any information that may help, contact Crime Stoppers on 1800 333 000 or report online to www.crimestopperswa.com.au