People are warned to be on the lookout for fake notes after some had been used in shops, including Tesco Metro in St Andrews.
Police are urging businesses to be extra vigilant about bogus Bank of England £50 notes in circulation.
It follows two incidents of counterfeit notes being used at Tesco in Market Street, St Andrews, and Lloyds Pharmacy in Cupar on Thursday April 6.
The culprit was described as a teenager of 13 or 14 years old, with brown hair in a buzz-cut style and gaps in his teeth. He was said to be 5ft tall and was wearing a grey hooded top.
Sergeant Paul Gillespie said: “Shops and businesses should make sure staff check all notes thoroughly when taking payment.
“Anyone who comes across a suspect note is advised in the first instance to report this to police.”
Gap-toothed teenager sought after fake notes used in shops
