Sussex Police was called to an incident at a betting shop in the Patcham area of Brighton on Sunday evening (September 8).
A spokesperson explained: “Police are investigating an attempted robbery at Ladbrokes, Carden Avenue, in Brighton, on Sunday evening.
"A man entered the shop at around 7.30pm, threatened a member of staff and demanded money before leaving.”
Four police cars were spotted at the scene, supported by the police dogs unit.
No arrests have yet been made but the police said detectives are on the the case and are ‘following a number of lines of enquiry’.