Police would like to trace this man after the victim of an assault lost a number of teeth.
The 26-year-old victim was punched to the ground in Carlton Street, Nottingham city centre, on 17 June after coming to the defence of a friend, who had been assaulted by a man.
Officers have pursued a number of lines of inquiry to identify the man in the image as it is believed he will be able to assist the investigation.
They are now turning to the public for help.
Anyone who recognises him is asked to call police on 101, quoting reference 26000359821.
Information can also be reported anonymously via Crimestoppers on 0800 555 111.
