Officers have received a number of reports over the last few days, many from elderly and vulnerable victims.
Those targeted have received calls or voicemail messages from a well-spoken man claiming that the victim owes unpaid tax and could be arrested unless they pay through the purchase of vouchers.
Sergeant Sam Ieong, of Leeds Police, said: “If you receive unsolicited telephone calls from anyone claiming to be from a government agency and saying you owe them money and could be arrested if you don’t pay, then we would advise people to be very wary and to contact the police.
“In some cases people have been told to buy iTunes or other vouchers to pay the amount back. We would advise people not to do this and to contact the police or Action Fraud.
“We are asking people to be vigilant and not to pass on any personal or bank details to anyone they are not expecting a call from.
“Never feel under pressure, you are under no obligation to give them personal details over the telephone.”
Anyone who receives such a call can report it to police by calling 101, or contact Action Fraud directly on 0300 123 2040. Reports can also be made online by visiting their website at www.actionfraud.police.uk