People pretending to be police officers have been carrying out phone scams in Bourne, Skegness, Chapel St Leonards and Boston.
A Lincolnshire Police spokesman said the force had received about 20 reports of attempted scams in the last few days.
People said they had received phone calls from men purporting to be detectives from Skegness police station, asking for bank card details because they had somebody in custody on suspicion of falsely using the cards. The potential victims were asked to hang up and redial 101 to verify that the “officer” was genuine.
The spokesman said: “This scam is a variation on recent frauds where the caller claims to be from the Metropolitan Police. The fraudsters keep the line open so that when the victim makes a call thinking they have got through to the police or to their bank, they are actually still speaking to the criminals.
“This scam has led to victims across the UK losing many thousands of pounds, often their entire life savings.
“Fortunately, increased awareness about the scam is helping to protect people and none of the people targeted this week fell victim to the scam so Lincolnshire Police want to thank Lincolnshire people for helping to spread the message. However, it is a reminder that scammers are still operating in our county and we should all be vigilant.
“Ensure your relatives, neighbours and friends all know about the scam and what to do if they receive a suspicious call.”
Read more about the scam at www.lincs.police.uk.