Shopkeepers in the Highlands are being urged to be extra vigilant following numerous cases of fraud known as “ringing the changes”.
The crime involves a person asking a member of staff to exchange a large sum of money into notes of smaller denominations.
The conman then deliberately confuses the staff member to obtain more money than they handed over.
The most recent incident was in the Hilton area of Inverness last Thursday evening.
The fraudster gained a three-figure sum. Inquiries are continuing to trace the thief.
Sergeant Richard Ross said: “I’d urge all business owners to ensure that their staff are aware and alert to this type of scam. In particular, to watch out for anyone asking to exchange large amounts of money.
“These people are using sleight of hand to leave the store with more money than they came in with. It’s possible they could target during a particularly busy time which provides an ideal opportunity for the criminal to confuse or distract you.
“If you’re in any doubt consider asking another colleague for assistance or politely decline the request and notify the police.”
Some retailers now display signs informing customers that they will not exchange large amounts of money, to discourage the scam.