This man may hold the key to an assault investigation.
Police have released CCTV images of the man because they believe he may have witnessed a serious incident outside a York nightclub.
The attack happened outside Flares on Tanner Row at around 4.15am on March 25.
The victim, a 36-year-old man from York, sustained a nasty head injury which required treatment at York Hospital.
It is believed the man in the CCTV footage was standing nearby when the assault happened and could hold vital information to assist the ongoing investigation.
He is urged to come forward to help the police. Anyone who recognises him is also asked to get in touch to provide a name and contact details.