Businesses are being warned to remain alert following reports of a scam.

A post on the Norfolk Trading Standards Facebook page warned people to "be aware of cold callers" visiting premises "offering to sharpen and coat tools and blades."

It comes after an incident in Norfolk where a staff member at a company was approached by two men who offered this tools and blades sharpening service.

The 'scam alert' post said: "The member of staff then agreed to an offered 'free sample' of the service and handed over an item to be sharpened.

"When the item was returned the cold caller then demanded a large payment, which the business refused to pay.

"The males were seen to return to a large black 4x4 with foreign number-plates.

"It is possible these cold callers could move on to other locations in Norfolk.

"Our advice is always to be very wary of claims made by cold callers to your premises and never agree to services, buy items or for return visits if approached in this manner.

"If you receive a cold call to your business from someone offering to sharpen and coat tools or blades we would advise that you decline the offer, ask the cold caller to leave your premises and then report the incident to us on 03454 04 05 06 or to Norfolk Constabulary on 101."