The British Transport Police are trying to trace a man who sexually assaulted a woman on board a train between Paddington and Reading.
The victim fell asleep on the train in the early hours of last Sunday. She awoke to find the man touching her.
The BTP has released a CCTV image of a man they want to talk to who got off the train at Reading. Anyone with information can call them on 0800 40 50 40 or the charity Crimestoppers anonymously on 0800 555 111 and quote reference GSUB/B5 of 27/08/14.