Lorna Brooks only realised that she was a victim of online identity fraud when she received a call from Mastercard about a change to her billing address. Brooks, a 55-year-old from Aberdeen, was confused because she had made no such request.

By that time a couple of unauthorised purchases had already been made on her account using details obtained by an internet hacker. Though the card company refunded the money, her credit rating plummeted.

“It really gave me a terrible fright,” she said. “And then when I was refused a phone credit because of my low rating, I felt so angry, so humiliated. Since then I have been very careful – I shred everything, and I have a separate credit card for internet purchases, with a low credit limit.”

John Lewis, 50, from Worcester, is also a recent victim of online fraud. After his details were stolen, he was faced with a bill of £4,500 spent on holidays and internet shopping.

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His bank, a major high street name, paid off only part of the amount. Eighteen months later he is still locked in a dispute about cancelling the rest of the debt.

“It was difficult to prove that the internet transactions weren’t mine, even though my wife and I hardly ever use online shopping,” he said. “The help they gave me in resolving the problem was absolutely appalling. I certainly won’t go doing anything online ever again.”

Not all identity fraud takes place online. Often the perpetrators are people in close contact with the victim, or their relatives. Indeed, banks often quiz victims about whether they would like an investigation to be launched, warning that it could lead to a family member or friend being prosecuted.

Among such victims is Gerwyn Bowen, 59, from south Wales. He found that four credit cards were fraudulently set up in his name after he left his bank statements lying around. “I was angry the credit companies did not run proper checks when handing out cards,” he said.

Wanda Robson also had her personal details used fraudulently. She was renting out a room in her house to a friend of a friend when he stole her details and spent £17,000 on her account. The 31-year-old animal technician from Peterborough said she was “very distressed” by the incident and now has problems getting credit.

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