A man exposed himself and performed a sex act on an afternoon train in front of a 14-year-old girl and her mother.

British Transport Police (BTP) have released an image of a man they want to speak to in connection with the crime on November 8.

The pair were travelling back to Romford on the 4pm Liverpool Street to Shenfield line after going to the Tower of London poppy display.

Det Con Michael Hatcher said: “The pair took seats in different areas of the carriage. A man sat opposite the girl and exposed himself before performing a sexual act.”

The girl went to tell her mother, but as the train pulled into Seven Kings station, the man got off the train.

DC Hatcher said: “Both mother and daughter were shocked by this incident.

“BTP has done a lot of work around incidents of unwanted sexual behaviour on the rail network, and we treat crimes such as this very seriously.

“I believe the man in the image we are issuing today can help with our investigation.

“Do you recognise him? Please get in touch.”

Anyone with information is asked to contact British Transport Police on 0800 40 50 40, or text 61016, quoting reference ESUB/B6 of 21/11/2014. Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.