A fraudster who tried to trick a 65-year-old woman in Redbourn out of thousands of pounds by buying iTunes vouchers failed when she became suspicious and immediately hung up on his cold calls.

Although the woman, who was targeted several times by the alleged scammer, avoided being conned, other people have been tricked and have lost tens of thousands of pounds.

Hertfordshire Constabulary has issued a warning about the scam phone calls, which have seen older people across the county conned out of about £60,000 within a fortnight.

In Rickmansworth, a 70-year-old woman was persuaded to purchase a total of just under £22,000 worth of vouchers, in three separate transactions during May.

Between May 16 and 17, an-83-year-old man from Northwood was tricked into purchasing £10,000 worth of iTunes vouchers. He was contacted again a week later and had just purchased a further £15,000 worth when police intervened.

A second man from Northwood, aged in his 80s, was also instructed to buy £10,000 worth of vouchers by fraudsters claiming to be from HMRC.

Staff intervened on this occasion and prevented him from purchasing them.

Detective Sergeant Jon Leak, from Hertfordshire Constabulary’s Operation Manhunt unit, said: “While we have been made aware of numerous scam phone calls across the county, this is a new method which we haven’t previously seen in Hertfordshire and I would urge people to remain vigilant if they receive calls of a similar nature.

"Legitimate organisations would never request payments to be made in this way.

“Unfortunately, these fraudsters are very convincing and their actions can have a devastating effect on their victims.”

DS Leak added: “I would like to hear from anyone else who has been contacted in similar circumstances, as the information could greatly assist our investigation.”