A man allegedly punched a woman in the face during an assault in Lincoln City centre.
A man, described as wearing a black and red puffa jacket, was on Guildhall Street in Lincoln on March 6 at 3.12am when the incident happened.
The female victim is in her 20s.
Police released an image of a man the force wishes to identify to assist with the investigation.
Anyone with information about the incident, or who recognises the person in the image, should contact Lincolnshire Police on 101 or via email at [email protected] quoting incident 18 of March 6.
It can also be reported anonymously through the charity Crimestoppers on 0800 555 111.