Police have renewed an appeal for Essex residents to be on guard against telephone tricksters following an increase in incidents in the west of the county.
Six elderly people in Harlow have been targeted since the start of December, including five on Monday.
Figures from the start of this month show that the thieves have called 38 people and tried to steal large sums of cash by claiming that they are police or bank officials.
The 38 offences since the start of December also include four in the Chelmsford area, three in Uttlesford, one in Colchester, three in Rochford, one in Basildon, nine in Brentwood, one in Epping Forest and 10 in Thurrock.
In nearly all cases they claim that a victim’s bank account has been infiltrated and that suspects have been arrested on suspicion of the crimes. They ask victims for their bank details and collect bank cards to use as "evidence”. But the cards are used to steal money from the accounts.
Of the 38 incidents this month two have led to cards being handed over to the thieves. It is not yet known if the cards were used to withdraw cash.
A total of 530 thefts and attempted thefts have been reported in Essex since January, and similar crimes have been reported in the Met Police area and other counties. More than 80 people in Essex have been tricked out of money and the total stolen is more than £274,000.
Inspector Paul Wells said: "The suspects usually telephone victims, address them by their name and pretend to be a police officer from the Metropolitan Police.
"They tell victims that their bank cards have been used in fraud and they need to take some personal details. The fraudster is sometimes able to reassure the victim that the call is genuine by telling the victim to hang up the phone and call them back.
"Through a loophole in the phone networks, the suspect actually remains on the phone to dupe the victim into thinking they are speaking with a legitimate person and giving their details, usually their card’s PIN.
"If they get this far, the suspects will generally send someone posing as a courier to collect the bank card, after which time it is used by the criminals.
"The same scam has been used with the suspects pretending to be calling from a bank.
"Victims of the offence have been elderly and we are not certain how they are being identified.
"We need people to tell elderly friends and family about this offence. It’s easily guarded against by hanging up the phone!"
REMEMBER • Police will never ask for your PIN.
• If you think you have been a victim, call police FROM A DIFFERENT NUMBER.
• If you don’t have another phone, use a neighbour’s, or wait five minutes before dialling 101 or 999 (if urgent).