Do you recognise this man?
Officers investigating a sexual assault on board a train from Chadwell Heath to Whitechapel have released these images.
On Monday 16 June at around 8am a man sexually assaulted another man as they stood near the doors of the train.
Detectives believe the man in the CCTV image may have information that could help with their investigation.
Anyone who recognises them is asked to contact BTP by texting 61016, or by calling 0800 40 50 40 quoting reference 688 of 16 June.
Information can also be given anonymously to Crimestoppers on 0800 555 111.
If you or anyone you know have been affected by the people highlighted in this website, then please report those individuals to the Police on 101 (999 if an emergency) or visit their online resources for further details of the options for reporting a crime. You can also make a report at Crimestoppers should you wish to be completely anonymous. There is help available on our support links page.