POLICE are calling for witnesses to an accident in Victoria's south that ended with a woman suffering life-threatening injuries.
A police officer was travelling west on the Geelong-Portarlington Road in Portarlington when a car speed past him about 4pm (AEDT) going in the opposite direction.
The officer switched on his blue lights and turned around, but lost sight of the speeding car over a hill.
He continued travelling east along the road and saw the car had crashed and was alight.
"With the assistance of several passers-by, he managed to get the woman from the burning car," a police spokeswoman said.
The 22-year-old female driver, of Craigieburn, was airlifted to The Alfred hospital with life-threatening injuries.
The Major Collision Investigation Unit will investigate the crash, overseen by Ethical Standards Command.
Police are appealing for witnesses to contact Crime Stoppers on 1800 333 000.