Police are appealing for witnesses after a man allegedly exposed himself at a reserve in Newport last month.
The alleged incident occurred on Thursday 21 February between 1.30pm and 1.50pm.
Williamstown police have been told two female victims were walking within the Newport Lakes reserve when a man allegedly began to follow them.
When the pair reached a dead end and turned around, they allegedly observed the man naked and masturbating.
The females challenged the man and took a photo of him before he gathered his clothes and fled.
Investigators have released an image of a man they believe can assist with their investigation.
The man is described to be Caucasian in appearance, in his early 30s, 170cm, with a solid build and wearing dark clothing, a black cap and khaki hoodie.
Police are appealing for anyone who may recognise the man or has information about the incident to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au