A man was battered on a train by another passenger and left with a fractured eye socket.
A man in his 30s was punched in the face by another passenger on an LNER service travelling between London Kings Cross and Newark Northgate at 11.30pm on March 22. He later required a complicated operation.
British Transport Police released CCTV images on Thursday, June 27 of a man they believe has information which could help with the investigation.
PC Steve Duck from British Transport Police, said: “The victim was left with a very nasty injury which required a complicated operation. He still requires ongoing treatment, but thankfully his injuries are not life changing.
“I would be keen to hear from anyone who can help us identify the man shown in this CCTV image.
“If you know who he is, contact us by sending a text to 61016 or by calling 0800 40 50 40. You can also contact Crimestoppers anonymously on 0800 555 111.”