A man has died following a police pursuit and crash in Sydney's southwest, prompting a critical incident investigation.
Police said highway patrol officers tried to stop the driver of a Lancer shortly after 11.20pm on Thursday and a pursuit began when the driver failed to stop when directed.
A short time later the car struck a power pole on Eastwood Road, Leppington.
A male passenger was thrown from the vehicle and died at the scene.
The driver is under police guard in hospital where he is undergoing treatment for injuries to his arm.
Police said a critical incident team will investigate all circumstances surrounding the crash and the investigation will be subject to independent review, with all information provided to the coroner.
Police are appealing for witnesses to come forward.