Transit Crime Investigation Unit detectives are investigating after a sexual assault at a CBD tram stop last month.
Police were told an unknown man was seen loitering around the D15 tram stop on Collins St, Docklands about 2.50pm on June 26.
It is believed the man approached a 17-year-old girl and took a photo with her before inappropriately hugging and touching her.
After the unwanted contact, the girl boarded the next available bus, while the man remained at the tram stop before walking west on Collins St towards Capital Hill Drive.
Investigators have released a computer-generated image and still images of a man they believe may be able to assist them with their enquiries.
He is perceived to be of Indian or Sub-Continental appearance and is approximately 160cms tall with a black moustache and short black hair.
He was seen wearing a white business shirt with black dots, dark blue or black trousers, a Louis Vuitton belt and black shoes.
He was also carrying a black backpack and wearing a gold banded watch with a white face.