Sexual Crime Squad detectives are appealing for witnesses after a woman was sexually assaulted at Pakenham in July, Victoria Police say.
The incident happened when a woman accepted a lift from a man on the Princes Highway at Beaconsfield on Sunday 30 July.
The 49-year-old Pakenham woman got into the white single-cab, flat-tray utility 100 metres west of Whiteside Road just before midnight.
The male driver drove the woman to Starling Road in Officer where he sexually assaulted her.
The man is perceived to be of Caucasian appearance, aged in his 50s, with a medium build and sandy hair which was short on the sides and curly on the top.
The man told the victim that he lived in Warragul.
The vehicle is described as being similar to a white 2001 Toyota Hilux single-cab, flat-tray utility. The utility tray is brown in colour with no sides or back.
Investigators have released an image of a similar type vehicle and a computer-generated image of a man they believe can assist their enquiry
Investigators are urging anyone with information to contact Crime Stoppers.