The unprovoked attack took place on Saturday, 8 October as the victim and his two brothers were returning from a night out via the 10.22pm Leeds – Hull service.

The victim, a 27 year-old man from the Selby area, received a bleeding eye, which later became bruised.

Transport Police officers have now released CCTV images of a man they would like to identify in connection with the incident.

Investigating officer, PC Nick Storey said, 'During the journey a man who is believed to have been drinking approached the victim, a 27-year-old from Selby, and leant on his shoulder.

'After a while when the victim asked him to move from his shoulder, the man suddenly punched the victim’s face. To escape the violence, the three brothers moved to a different train carriage. When the train arrived into Selby, the three brothers and the man left the service.'

BTP previously appealed for information through the media but to no avail. Now, hours of CCTV have been viewed and these images have been released in a bid to identify those involved.

PC Storey added: “This was a violent assault on a man who was simply trying to make his way home from an enjoyable night with his brothers. I’d appeal for anyone who was onboard the service, witnessed the nasty incident or who may recognise the man in the picture to come forward and help police with their investigation.”

Anyone with information should contact British Transport Police on 0800 40 50 40 quoting background reference B8/NEA of 30/12/2011. Information can also be passed to the independent charity Crimestoppers, anonymously, on 0800 555 111.