British Transport Police (BTP) detectives are searching for a man for indecent behaviour on the Central line.

A woman was approached on a westbound train at South Woodford Station on November 14 by a man who got on at the station.

Shortly before 4pm, the man tried to start a conversation with the woman about the destination of the train.

At this point, she noticed he had his hand down his trousers.

Detective Constable Jennifer Brown said: “The man got off the train at Snaresbrook and stood in front of the woman’s carriage.

His hand was still in his trousers and he appeared to be touching himself inappropriately.”

As part of their investigation into the incident, detectives have reviewed CCTV from the station.

DC Brown said: “I think the man in the image we are releasing today has key information about what took place.

“Do you know him? Please contact BTP?”

Anyone with information is asked to contact British Transport Police on 0800 40 50 40, or text 61016, quoting reference TSUB/B17 of 19/12/2014.

Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.

BTP has launched ‘Project Guardian’ a long-term project involving BTP, Transport for London, the Metropolitan Police and the City of London Police, which aims to reduce sexual assault and unwanted sexual behaviour on public transport in London.

According to their figures 15 per cent of females have experienced unwanted sexual behaviour on London’s Tube network, although many are said not to report it.