Police are calling for public assistance after a blind woman was indecently assaulted on Sydney's train system earlier this month.
The 23-year-old woman told police she was in a lift at Ashfield Train Station between 11am and noon on July 17 when an unknown person touched her breast.
The woman then caught a train to the city and then another train to Gymea.
She told police she was touched on the breast again when the train was between Jannali and Sutherland and a male voice spoke to her.
The woman moved to another seat but the man followed her and spoke to her again before walking away.
Police have released security footage of a man they would like to speak to over the assault.
Detective Inspector Robert Cipolla says it appears the man targeted the woman.
"She's a vulnerable person, she has a walking stick to aid her to get around, and it is a particularly appalling sort of crime to commit against a person or a member of the public like this," he said.
The man is of Indian appearance, carrying a backpack and wearing a brown and white-striped jacket.
He is about 170cm tall with a thin build.
Anyone with information is urged to call Crime Stoppers on 1800 333 000.