A rail conductor was assaulted by a passenger after asking to check his ticket.
Police are appealing for information about the incident which happened at Kirkham station at around 9.30am on Monday June 20.
The incident occurred on the 9.21am Blackpool to Huddersfield service
PC Ryan Moore, of British Transport Police, said: “During a routine ticket check a passenger on the service complained that he had produced his ticket earlier.
“He eventually handed over his ticket but as the conductor walked away he shoved him in the back and became abusive.
“The conductor asked him to leave the service and he left the train at Kirkham. On departing he made several threats to the conductor before throwing his coffee cup at the train as it left the station.
“Members of rail staff have a right to expect to be able to carry out their work without fear of intimidation, abuse or violence.”
After reviewing CCTV, officers are today issuing images of a man they want to speak to about the incident.
PC Moore said: “I want to speak to the man in the image as I believe he has information about what took place.”
Anyone with information is asked to contact British Transport Police on 0800 40 50 40, or text 61016, quoting reference 217 of 04/08/16.
Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.