Victoria Police have released CCTV and are hoping to identify a man following a sexual assault on a train from Thornbury.
Police have been told a woman boarded a city bound train at Thornbury Railway Station about 9.35am on 16 May.
The have described the attack in a statement:
"During the commute the woman has been repeatedly sexually assaulted by an unknown man. The 49-year-old woman moved away from him several times but he continually followed her.
She got off the train at Flagstaff Station and he continued to follow her and engage in conversation.
She alerted train station staff and the offender left the station."
The man was believed to be in his early 20s, of Islander of Asian appearance and around 160cm tall. He had a thin moustache.
He was wearing a navy New York Yankees baseball cap, navy baseball style jacket with white sleeves and beige pants.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report online at www.crimestoppersvic.com.au