British Transport Police are looking to trace a man they want to speak to after an assault on a train between Nottingham and Kirkby-in-Ashfield.
The incident took place at 9.40pm on Saturday, August 22 when a man became involved in an argument with another man after the train left Nottingham.
He walked away and sat alone before the other man confronted him again. The victim was then hit in the face, but did not receive any injuries.
PC Karl Laban said: “The offender left the station at Kirkby straight after the incident.
“If you know the man, or have any information about the incident, please give us a call on 0800 40 50 40 (quoting incident number MSUB/B7 of 17/11/15) or ring Crimestoppers anonymously, on 0800 555 111.”
PC Laban added: “We do not tolerate aggressive behaviour anywhere on the railway and we will do everything in our power to track down the person responsible and bring them to justice.
“I would like to appeal to anyone who may recognise the man pictured or knows his current whereabouts to contact police, as I believe he may have key information which could greatly assist our investigation.”