Officers are investigating an assault in which a 19-year-old had his jaw broken in an “unprovoked attack” after a night out in Long Eaton.
Police have released CCTV images of a man they are trying to trace in connection with the incident, on Main Street, on February 22.
The teenage victim, from Trowell, had been out drinking with friends and as he stood at the corner of Main Street and Clifford Street he was punched by a man.
A police spokesman said he was knocked off the pavement and into the road in an unprovoked attack.
He said: “The victim’s tooth was broken and as he got up to speak to his assailant he was hit again and knocked-out.”
The suspect is described as being white, with dark hair and stubble.
He was in his mid-twenties, 5’9” tall and was wearing blue shirt and jeans.
A number of people were in the area at the time and have not yet come forward.
Anyone with information should call 101 or call Crimestoppers anonymously on 0800 555 111.