A 20-year-old man was allegedly assaulted at a Lincoln nightclub.
The man sustained a facial injury after the assault at Moka nightclub on Silver Street in Lincoln on February 3.
Lincolnshire Police released a CCTV image of a man who they believe can help with the investigation.
Anyone who recognises the man pictured or has information about this incident should contact police on 101 quoting incident 28 of February 3.
It can also be reported anonymously to Crimestoppers on 0800 555 111.