Coral’s Bookmakers on Northampton Road, Wellingborough was robbed after a man holding a knife went in and demanded money from the member of staff.
The incident happened at around 6.30pm on Monday, 13 June. The member of staff handed over a quantity of cash and the offender made off.
The offender is described as wearing dark clothing and a face covering.
Anyone with information or who saw a man running from the shop can contact Northamptonshire police on 101. Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111.