Police in North Yorkshire are appealing for people to be vigilant after criminals conned their victims out of money by claiming be from the fraud squad.
Three fraud reports in York this week followed two similar incidents in Harrogate where unsolicited phone calls were used to target householders.
On Monday, an elderly woman in her 70s in York was phoned by a man claiming to be a "Sergeant Wiggins."
A police spokesman said: "He said that there has been suspicious activity on her account and that they needed her to visit a shop on Coney Street, York to purchase a Rolex watch, some euros and some money to help to rectify the situation."
At 10pm yesterday, a man calling himself Jamal turned up at her house with the password "sunflower", which had been given to the victim over the phone. He left with the watch and cash, worth Â£40,000.
In a second incident, a York husband and wife, both in their 70s, were contacted two weeks ago by a man claiming to be a fraud squad officer.
The couple were tricked into withdrawing Â£3,000, which was collected on Friday, April 20, by a man who went to their house.
In a third incident, a woman was called by a man called "Brian Park" who said he was from Natwest bank's fraud squad.
He claimed somebody had tried to use her account to pay for goods worth Â£1,645 at Homebase and John Lewis.
She was then called by a person claiming to be from HSBC who said the police were investigating. The woman was convinced to transfer Â£7,800 to an account number given over the phone.
The York incidents follow similar reports in Harrogate of telephone fraudsters who conned victims into withdrawing cash.
Detective Inspector Jonathan Rowland, of North Yorkshire Police’s Economic Crime Unit, said: “These fraudsters are extremely well organised and rehearsed and use a range of tricks and lies to convince their victims into trusting them.
“We cannot stress enough that the police or anyone from a bank would never ask you to withdraw or transfer money, or send someone to collect money from you, even with a password.
“If you have any doubts at all you should always hang up and call the police immediately or speak to a family member.”
“If you believe you or a family member have been a victim of this type of crime, please call us on 101 or report it to Action Fraud by visiting actionfraud.police.uk or by calling 0300 123 2040. In an emergency dial 999."