West Yorkshire Police are warning people not to give out their personal banking details to cold callers.
This follows three recent reports where a caller has pretended to be a police officer querying fraudulent transactions on bank accounts.
The caller has then asked for bank details, claiming that this will prevent further fraudulent transactions.
In one incident, a woman was duped into handing over gold jewellery to an unknown male.
He attended her house in Eccleshill in Bradford on 23 April after she told the caller she was afraid to keep it in the house after a burglary three years ago.
He is described as Asian and is believed to be in his late twenties, about 5ft 8ins tall and of slim build. He had a short beard, short black hair and was wearing a black hooded top and blue tracksuit bottoms.
Police have stressed that they would never ask someone for their banking details or call to speak about suspected fraudulent activity on their bank account.
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