British Transport Police have released an image of a man who they want to speak to as part of an investigation into a sexual assault.
The incident happened on the 6.49pm Euston to Birmingham New Street service – which passes through Kings Langley, Apsley, Hemel Hempstead, Berkhamsted and Tring train stations.
A 25-year-old woman who boarded a carriage towards the front of the train at Euston fell asleep, only to be woken as the train passed through Leighton Buzzard, by a man sexually-assaulting her.
The woman left the train at Milton Keynes and alerted police. Officers met the train at Rugby, but the man was not on it.
The assault happened on Wednesday, August 13 – but British Transport Police has just released the image of him.
Sergeant Mark Summerfield said: “Since our initial appeal for information on this incident, we have been able to isolate a CCTV image of a man who I am confident can help with our investigation.
“Do you know him? Please contact British Transport Police if you do.”
Anyone with information is asked to contact British Transport Police on 0800 40 50 40, or text 61016, quoting reference MSUB/B7 of 21/08/2014. Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.