Police have released an image of a person they wish to speak to after two women reported a man masturbating on London trains.
Officers are investigating allegations of two incidents in two days.
On August 29, shortly after 6am, a report was made by a woman of an offence on a train from East Croydon to London Bridge, British Transport Police (BTP) said.
The following day, at around 9.15pm, it is alleged a man followed a woman on a train from West Hampstead to Bedford and again carried out a sexual act.
Officers believe the man in the CCTV images may have information which could help their investigation.
Anyone who recognises him or has any further information, should contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 2200088600.
Alternatively, contact Crimestoppers anonymously on 0800 555 111.
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