Frankston Sexual Offences and Child Abuse Investigation Team are investigating after a man exposed himself in Rosebud.
Police have been told a 13-year-old girl was waiting for a bus on Point Nepean Highway about 6.30pm on 28 April.
A man approached the stop and exposed himself to the girl.
Both parties then caught the bus to Tootgarook where the girl disclosed the incident to a fellow passenger.
The man got off the bus before police were notified.
The offender is perceived to be Caucasian, about 20-years-old and with a thin build.
At the time of the offence, he was wearing a white jumper, black shorts, runners and was carrying a black bag.
Investigators have made a number of enquires in an attempt to identify the man but have so far been unsuccessful.
A computer-generated image of a man that may be able to assist police has been released.
Anyone with information about the identity of the man is urged to call Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au.
