Man sought after woman repeatedly sexually assaulted on train

A woman has been repeatedly sexually assaulted by a stranger on a train as she travelled to Melbourne last week.

The 49-year-old woman boarded the train at Thornbury about 9.35am on May 16 and was repeatedly assaulted by the man who followed her when she moved several times and got off the train with her at Flagstaff, police say.

Victoria Police have released images of a man described as being of Islander or Asian appearance. Source: Victoria Police

Victoria Police have released images of a man who may be able to help with enquiries.

He is described as being of Islander or Asian appearance, 20 to 25 years old, about 160cm tall and slim with a thin moustache.

He was wearing a navy New York Yankees baseball cap, navy baseball style jacket with white sleeves and beige pants, and fled when the woman alerted station staff.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000.