At 7.45pm on New Year’s Eve, a man was on board the Staines to Clapham Junction service.
He’s reported being sexually assaulted by another man already seated.
Officers would like to speak to the man pictured, as they believe he may have information that could help their investigation.
Anyone who recognises him is asked to contact British Transport Police by texting 61016 or by calling 0800 40 50 40, quoting reference 266 of 1 January.
You can also contact Crimestoppers anonymously on 0800 555 111.
