Police are searching for a man after a teenager was touched inappropriately on a train in Brentwood.

British Transport Police (BTP) have released this CCTV image of a man they want to speak to in connection with the incident.

The 18-year-old girl from Ongar boarded the train at Brentwood at about 8.50am on Wednesday. March 14.

Detective Constable Alan Reed, investigating officer, said: “Throughout the journey she noticed a man, who was already on the train when she boarded, staring at her, which made her feel extremely uncomfortable.

“They both left the service at Shenfield to board another train heading towards Chelmsford. Whilst on the second train, she felt him touch her inappropriately on the leg.”

Police said they have conducted several lines of enquiry, including visits along the routes and speaking to regular commuters.

Officers said after viewing CCTV footage they wanted to speak to this man who may have “key information about the incident.”

DC Reed added: “This must have been a very frightening experience for the victim, who felt she was being followed.

“Incidents like this are very rare on the rail network but we treat them very seriously. I’d ask anyone who recognises the man pictured, or if indeed you are him, to come forward and assist us in this investigation.”

Anyone with information is asked to contact British Transport Police on 0800 40 50 40 quoting B5/LNA of 03/05/2012.

Information can also be given to Crimestoppers, anonymously on 0800 555 111.