British Transport Police officers are looking for a man following an incident on a train journey between Lancashire and Cumbria.
Two CCTV images have been released, showing a man officers want to talk to, after a train guard was assaulted on the late-night service.
PC Gavin Daw said: “As the 9.15pm service from Lancaster to Barrow-in-Furness made its journey north, the female guard was assaulted.
“As the guard walked through the train, a male passenger placed his hand on her upper thigh.
“I have released two CCTV images of a man I want to identify. I believe he has information about the incident.
“If you recognise the man in the images, please contact British Transport Police.”
The incident happened on Saturday, August 23.
Anyone with information on this incident should contact British Transport Police on 0800 405040, or by text, on 61016, quoting reference B2/PSUB of 2 October 2014.
Information can also be passed anonymously to Crimestoppers on 0800 555 111.