Mandurah Detectives are currently investigating a carjacking incident that took place on Park Road last Thursday.
Police say a 42-year-old man was driving his black Ford Falcon sedan at around 8.55pm on October 20 when another vehicle stopped in front of him and reversed into his car.
A man then exited the vehicle armed with a knife and threatened the driver.
The victim exited his vehicle and the offender and the other vehicle drove off.
The stolen car, WA registration 1ENF449, is still outstanding.
The offender is described as being approximately 180cm tall, with a slight build and tanned complexion.
Mandurah Police urge anyone who has information relating to the incident or dash-cam footage to contact Crime Stoppers on 1800 333 000.