Transit Crime Investigation Unit detectives are investigating after a man performed a lewd act on a bus in Glen Waverley in April.
Police were told a man got on a bus at Glen Waverley Railway Station and engaged in sexual activity directed at a 17-year-old girl about 11.05am on Friday, 21 April.
The 753 service was heading towards Bayswater and it is understood the man got off at Jells and Ferntree Gully roads.
Investigators have released an image of a man they believe may be able to assist them with their enquiries.
He is described as medium build with a bald head and short grey hair on the sides. He may also be using a crutch or walking stick.
The man was last seen wearing a black coat and blue jeans with a grey shopping trolley and a green bag.
Anyone who recognises the man or has information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au
