A member of staff at a shop in Park Farm Road spoke to a man following a reported theft shortly before 6pm on Friday 29 January 2021.
The man is reported to have headbutted the member of staff before leaving the store.
Enquiries into the incident are ongoing and officers are releasing a CCTV image of a man they believe may be able to help the investigation.
Anyone with information should call Kent Police on 01843 222289, quoting reference 46/15022/21.
You can also contact the independent charity Crimestoppers in Kent anonymously on 0800 555 111, or by visiting crimestoppers-uk.org