Transit Crime Investigation Unit detectives are investigating a sexual assault on a bus from Hallam to Narre Warren last month, Victoria Police say.
Investigators have been told a 17-year-old girl boarded the bus on Frawley Road, Hallam just after 1.50pm on 17 September and placed her bag on the seat next to her.
An unknown man approached the victim, removed her bag from the seat and placed it on her lap.
He then sexually assaulted the victim and made inappropriate conversation before disembarking the bus at a shopping centre on Overland Drive, Narre Warren.
Detectives have released CCTV footage and still images of a man they believe can assist with their enquiries.
He was perceived to be Middle Eastern in appearance, aged in his 30s, with a receding hairline.
He was wearing a black suit jacket, sunglasses, and spoke with a heavy accent.
Anyone with information is urged to contact Crime Stoppers.
