Commuters are being asked to watch out for a serial flasher after a string of “disgusting” incidents on trains across London.
A manhunt has been launched after four different people spotted a man exposing himself and then touching himself inappropriately while on Thameslink trains in the capital.
Then in December, two more people spotted a man touching himself between St Pancras and Brighton and East Croydon and Gatwick Airport.
The fourth and most recent incident was on a Thameslink train between St Albans City and West Hampstead on April 2 when the man exposed and touched himself inappropriately in front of a woman, aged 61.
Detective Constable Allan McTaggart said police believe the suspect may work somewhere on the Thameslink line or live near to one of the stations.
The British Transport Police officer said: “Therefore, I’d ask passengers who regularly commute on this line to be particularly vigilant.
“If you know the man shown in the CCTV image or spot him on your travels please get in touch – he may have information which could be vital to the investigation.
“In all of these cases, the suspect has changed his clothes after he has exposed himself to passengers. If you have noticed a man acting suspiciously in this way, again, we would like to hear from you.”
Images of the suspect have been released by the police.
DC McTaggart added: “We will not tolerate unwanted sexual behaviour such as this and I would like to thank each of the victims for reporting these disgusting incidents to us.
“Every report of a sexual offence builds a picture and helps us to track offenders and bring them before the courts.”
Anyone with information is asked to send a text to 61016 or call 0800 40 50 40 quoting reference 311 of 26/04/2017. Alternatively, pass information anonymously to Crimestoppers on 0800 555 111.