A brave shopkeeper confronted a knife-wielding robber thought to be behind a string of similar incidents in Derbyshire.
CCTV of the incident has been released as Crimestoppers offer a reward of up to £1,000 for information they exclusively receive which significantly assists officers in their investigation.
The video shows the suspect, dressed in a bright orange jumper, and holding a knife, grabbing the shop till.
It falls and as the suspect attempts to open the till, the shopkeeper uses the mop to fight him off.
The suspect leaves but then returns and appears to take money.
Police said significant amounts of cash have been stolen from shops in Derby and Ilkeston during seven robberies in recent weeks.
The offender in each incident was armed with a knife but did not harm anyone physically during any of the incidents.