Fraudsters are conning elderly victims by pretending to be bank workers to get their account details.
Victims in Chesterfield have fallen prey to the criminals, who call residents claiming to work for the bank they have an account with.
They claim there has been fraudulent activity on their account before asking for a PIN code.
Residents are told a courier will collect their debit cards and are encouraged to call their bank to clarify the call is genuine.
But the fraudsters do not hang up, so the phone line remains open, and the victim is actually speaking to an accomplice rather than their bank.
A genuine courier firm, or a taxi firm employed by the scammers, then call at the victim’s house to collect the cards.
The victims, who are all elderly, later discover that money has been withdrawn from their accounts.
Derbyshire police have referred the crimes to the National Fraud Agency for investigation.
Officers are urging people to keep their PIN a secret and remember banks will never ask for a PIN code.
Anyone with information about these crimes should call police on 101.