Fraudsters claiming to be officers from Essex or the Metropolitan Police are continuing to target mainly elderly people into handing over their bank details or large sums of cash.
Their scam involves tricking their victims into believing their bank details had been obtained by thieves, who are said to be under arrest, and that 'police' need them to withdraw banknotes to be examined for fingerprints.
In the past month, four people in the Maldon, Chelmsford and Braintree districts have been tricked into handing over more than £27,000 to the thieves.
The thefts were at: South Woodham Ferrers on April 14 where £10,000 was stolen; Maldon on April 18 where £1,800 was taken, Chelmsford on April 22 where £8,250 was taken and Witham on April 24 where the thieves took £7,750.
In all the incidents couriers were sent by the thieves to collect the cash.
Two similar incidents at Braintree and Felsted, were foiled by bank staff who warned customers of the scam when they attempted to withdraw large sums of cash.
The victim at Braintree on April 10 had tried to withdraw £4,000 and the victim from Felsted had intended to give the thieves £3,000.
More than 20 other people in central Essex have received calls from the tricksters since the start of the month, including eight in one day in Maldon and three in Braintree, but they all realised the calls were scam attempts and contacted police.
More than 750 similar thefts and attempted thefts have been reported in Essex since the scam first came to light in January 2013, and similar crimes have been reported in the Met Police area and other counties.
More than 110 people in Essex have been tricked out of money and the total stolen is more than £380,000. Six people have been arrested in connection with the investigation.