Officers from British Transport Police are appealing for information after a man indecently exposed himself on a train near Clapham Junction station.
The incident happened on a train between Victoria and Brighton on Sunday, July 14, and the man left the train at Redhill.
Police have released images of a man they want to speak to in connection with the incident.
Police Constable Alexandra O’Leary, the investigating officer, said: "The victims, two women in their 20s, were travelling on the 5.50am Victoria to Brighton service.
"When the train was near Clapham Junction, they realised a man sitting opposite them was exposing himself.
"One of the victims confronted the man and then reported his behaviour to the train conductor. The man left the train at Redhill."
Enquiries are ongoing into the incident, and officers have obtained images of a man they believe has vital information about what happened.
PC O’Leary added: "We do not tolerate indecent behaviour of any kind on the transport network and take all reports seriously.
"If you recognise this man, or have any information that could help our investigation, please contact us."
Anyone with information is asked to contact British Transport Police on Freefone 0800 40 50 40 or text 61016 quoting reference B18/LSA of 01/08/2013. Alternatively, information can be passed to the independent charity, Crimestoppers, anonymously on 0800 555 111.
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