When Lisa Selby* used her debit card to pay for two slices of barbecued cheese from a beach vendor in Rio de Janeiro, she expected to pay 40 reais (£5.90) for the snack.

But shortly after the payment had gone through, she realised that she had been charged 4,000 reais (£590) after the vendor added two extra zeros to the card reader.

“He showed me the right number on the contactless terminal, but then turned it round to face him and, unbeknownst to me, added two zeros just as I was about to tap with my phone,” she said. “He then gestured that there was no paper for a receipt and walked away.”

Holidaymakers have been warned to beware of the crime in Rio.…