SWINDLERS are posing as policemen and Apple store workers to steal money.
Nine people are known to have been targeted since Monday.
Some incidents involved a telephone caller claiming to be a policeman investigating a fraud. Another caller purports to be from Apple, collecting a bill for thousands of pounds supposedly run up by a grandchild playing games on a mobile phone.
In at least one of the incidents a large amount of cash has been stolen.
Crime prevention officer Samantha Hancock said: "People are being persuaded to hand over personal details and this could lead to a huge loss of cash. This is a significant security risk and as police there are certain things that we would never be doing.
"It is highly irregular for police to need to come and collect credit and debit cards. If we ever do the police officer will come and collect them in person with formal identification.
"We would never send a taxi or courier ever."
The conmen have mainly targeted elderly people, although a couple in their 40s have fallen victim.
Calls have been received in Wollaton, Carlton, Bramcote, Gedling, Arnold and Clifton, sometimes at night.
A man claiming to be a police officer from a force elsewhere in the UK tells a potential victim they are investigating a fraud and asks them to ring the bank and cancel their cards.
Despite putting the phone down to make the call, the victim's phone line has been directed back to the scammers, who then ask for their bank details.
In many cases the person is asked to provide their full bank card details and key in their PIN so their existing card can be 'cancelled' and a new one authorised. The fraudster then explains the bank needs to collect the cancelled cards and arranges for a courier to visit the house within an hour.
A large amount of money is then charged to the credit card.
Ms Hancock added: "We've also had people pretending to be from the Apple store in London claiming that a grandchild has run up a bill of £1,000.
"In the 'police officer' cases the name PC Harrington keeps cropping up and a claim that two Eastern European men have been detained is also common.
"The most important thing is that people make sure they do not give out any card details or any other sensitive information.
"If people have given out card details they should ring their bank immediately before reporting it to police."
To report any incidents of fraud contact the National Action Fraud centre on 0300 1232040.
