Police are concerned there could be more victims of a man who lured a teenager onto a jet ski then sexually assaulted her in Melbourne's west last month.
Detective Acting Sergeant Adam Vaughan said the man approached the 15-year-old girl at the Altona Pier and offered to take her for a ride about 6:00pm on Friday, November 27.
"During that ride the male has taken her out into deep waters and has sexually assaulted her, before returning her back to the pier and her friends," Sergeant Vaughan said.
He said the girl was on the jet ski for about 20 minutes, and later reported the incident to the police.
"As hard as it was for her she recalled the incident with great detail, and she's going well but it was very traumatic for her," Sergeant Vaughan said.
Police said the young man was believed to be in his early 30s, of Middle Eastern in appearance, with dark hair and a beard, and was riding a red jet ski.
Sergeant Vaughan said there was evidence suggesting there could be more victims, and possibly other offenders also using jet skis to target young women.
"There are slightly different descriptions as well so that raises the possibility of other offenders as well," Sergeant Vaughan said.
He said it was very concerning.
"People go down to the beach to enjoy themselves and they don't expect for an incident like this to occur in such a populated area in the summer time when the weather is warming up," Sergeant Vaughan said.
Police are urging anyone with information to contact Crime Stoppers.
