Norfolk Constabulary has issued fresh warnings to people receiving phone calls from alleged police officers asking for bank details or cash.

Eleven residents in North Norfolk were targeted on Thursday by scammers claiming to be police officers investigating fraud cases. 

Victims were asked to provide bank details over the phone to assist the fake officers in their lines of enquiry.

Norwich Evening News: Some scammers have been arrested in the London area, but fake calls continue in Norfolk. Picture - Metropolitan PoliceSome scammers have been arrested in the London area, but fake calls continue in Norfolk. Picture - Metropolitan Police (Image: Metropolitan Police)

All 11 scams were unsuccessful, but Norfolk police inspector James Makepeace fears many people may have fallen for the scam.

The inspector said: "There are several vulnerable and elderly people who have sadly withdrawn large amounts of money and handed it over to people they believed were police officers.

"The police won't ever ask you to withdraw money and certainly never to hand it over."

Insp Makepeace said scams such as these have been increasingly seen across the country over the past three years.

Arrests have been made in the London area following investigations. But the scams have continued and recently occurred in Norfolk.

Norwich Evening News: Norfolk police inspector James Makepeace. Picture - Norfolk ConstabularyNorfolk police inspector James Makepeace. Picture - Norfolk Constabulary (Image: Norfolk Constabulary)

Organised crime groups have called people with false stories of investigations into counterfeit money in banks or investigations of individuals. The victims have then been asked to either provide bank details or even withdraw cash from the bank before handing it over to couriers allegedly investigating counterfeit notes.

Criminals have been able to access people's data through mailing lists or other subscriber lists, with scammers methodically choosing contact details of people with "older-sounding names".

"Quite often you see when there's a series of attempts in one district, the victims' names will appear in alphabetical order," Insp Makepeace said. 

"It's not always from the phone book as it's sometimes Christian names and generally older-sounding names."

There have been instances of victims questioning the purported investigations and being told to dial 999 to confirm. The scammers have stayed on the line and impersonated emergency call centre personnel confirming the fraudulent stories.

"It is quite an intricate scheme," Insp Makepeace said.

"And thousands of pounds have been stolen."

The police has a national agreement with banks, which encourages bankers to question suspected vulnerable people withdrawing large sums of cash.

If you have any doubt about the contact you have received from someone claiming to be the police, get the officer's collar number and where they work and dial 101.

To report a scam, call the Action Fraud team on 0300 123 2040.