Hazel said, “They said we’d won six days in Cancun and four in Florida. The guy I spoke to said he had our bank details in front of him and he actually knew which bank we were with.”

The technique is common amongst scammers, who choose the name of a large bank to give them a significant chance of guessing correctly — if the guess is wrong, the caller hangs up.

The caller said that Hazel’s account number — actually her bank card number — started with a 4. This is another common ruse, as every Visa Debit card in circulation begins with this number.

Hazel said, “A lot of people won’t know the difference between their bank card number and their actual account number and think the caller is genuine. You will get gullible people who think they’ve won a holiday.”

The callers, who had Indian and American accents, claimed they had Hazel’s details, as the company worked “in conjunction with other banks”.

Hazel said, “There’s no way my bank would give out my details to anybody. I’ve hung the phone up but they’ve phoned right back. I said that I didn’t feel comfortable giving out any details.

“I’m far from stupid but they do sound convincing and other older people could be taken in.”

After hanging up, a quick check on the Internet confirmed Hazel’s suspicions.

She said, “I went on the website and there was a forum with people complaining. As soon as they get details they take the money from people’s accounts.

“I’ve spoken to a couple of other people I know in the Hilltown and Linlathen and they’ve had calls from them as well.”

A police spokesman said, “People should always be extremely cautious about providing personal and financial details over the phone, particularly in instances where they have been cold-called.

‘‘Above all, if you have concerns or suspicions hang up and contact the police.”