Businesses are being warned by police to be aware of suspicious activity involving males attempting to buy high value items in shops.
A spokesperson said the purchases are ‘believed to be fraudulent’.
Shop owners are being urged to be on the look out for males entering their premises and attempting to buy expensive items with more than one payment method.
It is understood the men are sometimes using several cards to make a single payment.
Police say the transactions are suspicious because the ‘buyers’ are swiping cards on the machine and also pushing buttons on card readers.
Warning businesses, the spokesperson said: “Please be wary of this and inform staff. If you have persons you are suspicious of please phone 101 quoting crime CR/066373/19, or 999 if you believe a crime is taking place.”