A man was left with a head injury after he was allegedly assaulted outside The Scene nightclub in Lincoln.
The attack was reported on Tuesday, June 19 on Newland.
At around 12.40am the man, who is in his 20s, was involved in an altercation with another man.
Police said the victim was punched, fell to the floor and sustained a head injury. He was treated in hospital and later released.
An 18-year-old man was arrested and later released under investigation in connection with the incident.
Lincolnshire Police said: “Inquiries are ongoing and anyone you saw this incident and hasn’t already made a report is urged to do so. Please call 101 quoting incident 15 of June 19.”