Police are issuing warnings following a series of scam phone calls which have seen victims lose thousands of pounds.

Since the beginning of April, police have received 30 reports, mainly from people living in the St Albans, Watford and Hertsmere areas of the county.

In most cases, victims have been contacted by someone purporting to work for the police (or sometimes the bank), claiming that their card or bank account has been used fraudulently.

The caller then asks the victim to assist with the ‘police investigation’ by withdrawing large sums of money and handing it over to a courier.

In some cases, victims have also been asked to purchase foreign currency and high value goods, such as designer watches.

Detective Constable Carmine Zanfardino, from the Constabulary’s Serious Fraud and Cyber Unit, said: “Thankfully, many people recognise these scams for what they are and refuse to part with any money.

“However, there are occasions when people - particularly those who are elderly or vulnerable - do fall prey to the highly persuasive nature of these fraudsters and often lose thousands of pounds.

“The offenders try and gain trust by asking victims to dial another number, which they believe will put them through to a second police officer who will corroborate the story.

“In reality, the phone line is being held open and the victim is simply connected to another offender.”

If you think you may have been contacted in similar circumstances, please report this to police on the non-emergency number 101 or online at www.herts.police.uk/Report.