Police Scotland are alerting the public, particularly those who are employed in shops or regularly handle cash, to be aware of counterfeit banknotes, following recent incidents reported in Inverness and Nairn.
Detective Inspector Richard Baird said: "We have received a number of reports of counterfeit banknotes being used in the Inverness and Nairn areas in recent days.
These include First Trust Bank £50 notes which bear the serial number AA294395. These are being tendered for low cost items in shops in the Highlands and later being found to be counterfeit currency."
"We are advising those members of the public who are dealing with cash sales to bear this in mind and check high value banknotes before giving change. Anyone who deliberately uses counterfeit currency is committing crime and we will investigate all instances reported to us".
All reported incidents so far have involved men of different descriptions but police believe the incidents may be linked.
Anyone who has any information about those using the counterfeit banknotes or wishes to report having received one should contact Police Scotland on 101 or Crimestoppers on 0800 555 111.