The States police would like to speak to anyone who may have witnessed the incident or has relevant information.
The alleged assault and theft took place between 12.30 am and 1 am on 20 October on Plat Douet Road, St Saviour, in the area outside Samuel Le Riche House.
The victim was a male in his thirties, who was wearing a bright blue jacket and blue jeans.
Anyone with information can contact the police on 612612 or anonymously via Crimestoppers on 0800 555 111.