A picture has been released of a man police want to speak to after a woman was sexually assaulted on the beach at Middle Park on Saturday night.
Victoria Police acting Sergeant Melissa Seach said the incident happened on Saturday night on Beaconsfield Parade.
Sexual Crimes Squad detectives have been told the 31-year-old woman was running along the foreshore between Fraser Street and Langridge Street about 11pm to 11.30pm.
"She was grabbed from behind by an unknown man and forced face down into the sand before she was sexually assaulted," Sergeant Seach said.
"A man with long brown dreadlocks and a woman came to the victim's aid along with two other men wearing white shirts."
The offender who was wearing a dark coloured hooded jumper fled the scene.
He is described as Caucasian in appearance, 178 centimetre tall, medium build with light coloured eyes and light coloured hair.
Detectives have released a digital image of a man that may be able to assist with their enquiries.
Acting Sergeant Seach said investigators were keen to speak to the four people who assisted the victim and any witnesses in the area at the time of the incident.
Anyone who has information about the incident or the man's identity is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au.