A motorcycle rider was robbed at gun-point by a motorist driving a car behind him at Blacktown on Sunday.
About 12.20am the rider, a 20-year-old man from Concord, was travelling on Prospect Highway.
He said he noticed a vehicle close behind him and moved over to let it pass him, but it continued tailing him.
He thought it was a police car, stopped his motorcycle and dismounted.
The car's passenger pointed what was described as a Glock-style pistol at him, while the driver approached him and took his wallet.
The rider was not harmed.
He described the car's driver as 183 centimetres tall and wearing a black hoodie, wearing khaki cargo-style pants and carrying a Lonsdale man bag.
The passenger was also male.