Updated 29 March 2011 at 22:41
The victim received a broken jaw from a single punch requiring surgery and a metal plate having to be inserted to reconstruct the bone.
The suspect, who has been captured on CCTV, is believed to be responsible for breaking a man’s jaw outside Rehab, on Parliament Street, in the early hours of Friday 28 January 2011.
The victim, a 19-year-old man from Knaresborough, was standing outside the bar at approximately 1.30am, when he was engaged in conversation by a man who had been refused admission.
Following the conversation, the suspect punched the victim in the face, inflicting injuries which required surgery at Harrogate District Hospital, before making off along Oxford Street.
Police have conducted extensive enquiries in the area and are now appealing to the public to help identify the offender.
PC Steven Dougall, of Harrogate police, said: “This was a particularly nasty incident which left the victim needing surgery.
“The CCTV image shows a clear picture of the suspect and I am confident that someone will be able to help us identify him.
“I am appealing to anyone who witnessed the incident itself or can help us identify the suspect to contact the police or Crimestoppers with information.”
Anyone with information that can help the police with their enquiries is urged to contact PC Dougall, of Harrogate police, on 0845 60 60 24 7, quoting reference number 12110016306.
Alternatively, Crimestoppers can be contacted anonymously on 0800 555 111.
The image has also been added to the Caught on Camera section of the North Yorkshire Police website www.northyorkshire.police.uk/CaughtonCamera