People want to speak to the person in this picture, who they believe may have information about an incident of GBH in Buckingham.
Thames Valley Police is releasing CCTV images of a man who may have vital information relating to an incident of GBH on High Street, Buckingham, between 1am and 1.30am on Saturday 7July.
The victim, a man in his twenties, was punched to the face which caused him to fall to the floor and knocked him unconscious.
As a result of the punch he suffered facial injuries and was taken to Milton Keynes University Hospital and later Luton & Dunstable Hospital. He has since been discharged.
Investigating Officer PC Lisa Murton of Aylesbury station, said: "We would like to speak to the person pictured as he may have vital information regarding this incident.
"If anybody recognises him we would ask them to contact police."
Anyone with information can call 101, quoting reference number 43180205827, or report it online at https://www.thamesvalley.police.uk/tua/tell-us-about/cor/tell-us-about-existing-case-report/
You can also contact Crimestoppers anonymously on 0800 555 111.