Transit Crime Investigation Unit detectives are investigating an assault on a bus in Beaconsfield last month that left a man with serious injuries.
It is understood a passenger got on the bus on Old Princess Highway at 1pm on Sunday 4 June.
The male passenger was struck by another passenger several times in the head, causing him to lose consciousness.
The 53-year-old man was taken to hospital where he remained for three weeks and required two surgeries.
The offender is perceived to be of Middle Eastern appearance and described as being short, with a stocky build, brown hair and a beard.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at crimestoppersvic.com.au
