Scammers pretending to be officers from Dewsbury police station have been calling victims and claiming their bank card has been fraudulently used to buy goods and services.
Officers from Kirklees CID are advising people in the town to be aware of the telephone scam which has led to the theft of several debit and credit cards.
The fraudsters offer to collect the person’s card from their home in person or by sending a taxi.
The victims have predominantly been Asian families and the callers are aware of their name and address before they make contact.
Det Insp Steph Wiseman, of Kirklees CID, said: “We are investigating a small number of crimes and our enquiries are ongoing.
“However we wanted to raise awareness of what is going on to stop the number of offences from rising.
“West Yorkshire Police officers would never ask for you to hand over your credit or debit card or to give out any financial information over the phone and neither will any other reputable organisation, including banks.
“If someone rings your home out of the blue and asks for your bank details or your card, please do not give it to them and ring us on 101 to report it.”