Police are trying to trace a man after a teenage girl was raped on board a train travelling from Essex to London.
Detectives on Monday issued a CCTV image of a man they want to speak to in connection with the incident, which is said to have happened around 12.30am on Saturday, December 9.
The girl was sexually assaulted after boarding a train at Laindon station, around three miles west of Basildon, said British Transport Police (BTP).
The train had been travelling to West Ham in east London.
"Following a number of enquiries, officers believe the man in the CCTV image may have information which could help their investigation," said a BTP spokesperson.
Anyone who recognises him or has any other information is asked to contact BTP by texting 61016, or by calling 0800 40 50 40 quoting reference number 25 of 09/12/23.