Knox Sexual Offences and Child Abuse Investigation Team detectives have released a digitally generated image as part of their investigation into an incident where a man exposed himself in Warburton earlier this year.
A 17-year-old woman was walking along the Yarra River Walk near Redwood Centre when she observed an unknown man about 6.10pm on 10 January.
The man looked at the woman while masturbating before hiding behind bushes and leaving the scene when more walkers approached the area.
The man was perceived to have an olive complexion, of average build with dark-coloured hair and a beard.
Police have released a digitally generated image of a man they believe could assist with their enquiries.
Anyone who witnessed the incident, recognises the man, or has any other information that could assist police is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au