Moonee Valley Crime Investigation Unit detectives are investigating an assault, robbery and car theft in Ascot Vale last month.
Police have been told a 29-year-old man noticed his car missing from outside his address in Flemington on 22 March just after 10am.
The man tracked his vehicle via his phone to Ascot Vale and rode to the location on his bicycle.
He located his car on Churchill Avenue in Ascot Vale about 11am and was taking photos of it when he was approached by an unknown male.
The male demanded the victim hand over everything he had in his pockets and when the victim refused, he was punched to the head several times.
The offender stole the victim's mobile phone and a second set of car keys and took off in the stolen car.
The victim rode his bike to the police station to report the incident before being taken to hospital for treatment for concussion, bruising to eyes, blood nose and a cut lip requiring stitches.
The offender is perceived to be of Pacific Islander/Maori appearance, 184cm tall with brown eyes, short curly black hair and unshaven.
He was wearing a dark-coloured hooded top and grey track pants.
Investigators have released a facial composite of a man they believe may be able to assist with their enquiries.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au
