Police have released a CCTV image after a man took off his clothes from the waist down on a train and masturbated in front of passengers.

The incident happened on the London Bridge to Albany Park line on July 14 at some time between 7.13am and 7.49am.

British Transport Police investigating this incident of "outraging public decency" have released a photo of a man they would like to speak to.

Anyone who knows the man in the photo is urged to contact BTP by sending a text to 61016 or calling 0800 40 50 40 and quoting ref: 140 of 14 July.

Those who wish to remain anonymous can call Crimestoppers on 0800 555 111.