British Transport Police officers have released CCTV image following a report of threatening behaviour on board a train in North Wales.
The incident happened at 1.43pm on Monday 21 January between Wrexham General and Ruabon stations.
A man is alleged to have threatened to assault an off duty member of rail staff after they told him to stop smoking.
The man continued his threatening behaviour until he left the train at Ruabon station.
Anyone who recognises the man, or who has more information about the incident, is asked to contact BTP by texting 61016 or calling 0800 40 50 40, quoting reference number 227 of 21/01/19.