Transit Crime Investigation Unit detectives are appealing for public assistance after a man followed a woman onto a tram in Box Hill last month.
On Wednesday 17 June about 12.20pm, an unknown male offender boarded the tram outside the Box Hill Railway Station and proceeded to masturbate in the presence of the woman.
Police have released images of a male they wish to speak to in relation to the matter.
He is perceived to be Caucasian in appearance, with a medium build and dark short hair.
He is believed to have a distinctive scorpion tattoo on his left calf
At the time of the offence he was wearing a dark-coloured windcheater, dark-coloured Adidas shorts and had a moon boot on his right leg.
Anyone who recognises the man, or has information that could assist police with their enquiries is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au