Do you know who this man is?
Detectives investigating a sexual assault on board a train travelling between Stratford to Ilford are looking to identify him in connection.
At approximately 5.25pm on 11 December, a woman was touched inappropriately below the waist by a man she did not know.
The incident happened on board a busy train service. The victim moved away, but the man followed her and continued to be inappropriate.
Officers believe the man shown in this image may have information which could help them investigate.
If you know who he is, contact BTP by sending a text to 61016 or by calling 0800 40 50 40 quoting reference 425 of 11/12/2018.
Or ring Crimestoppers anonymously on 0800 555 111.