Researchers downloaded free software from the internet, and were able to recover
22 000 supposedly ‘wiped’ files from the drives, including images, and spreadsheets.

The research was provoked by reader, Alexander Skipwith, 39, who reported that he had been told that his faulty hard drive would be wiped of confidential information before it was sent back to the manufacturer. He later had the allegedly ‘deleted’ documents held to ransom by a man, apparently from Latvia, who sent personal photographs as proof that he could access the files, charging £100 for the safe return of the files.

Skipwith told the magazine: “I spoke to the police and there was a difficulty in establishing what was in their jurisdiction and what crime had actually been committed. The emails had been cleverly worded and the police reminded me that he had paid for the drive.

“He had purchased it legitimately, which was not a crime and it was difficult to establish at what point a crime had been committed from their perspective.

“Basically if he had asked for a specifically large amount of money it would become exhortation. But the whole undertone was very threatening”.

According to the magazine’s editor, Sarah Kidner, the average UK citizen is worth approximately £85 000 to an identity fraudster.

“It sounds extreme,” advises Kidner, “but the only way to be 100% safe is to smash your hard drive into smithereens.”

The magazine gives the following tips.

1. Delete your data properly
It’s your data on your hard drive, so it’s your responsibility. Even if you give your PC to a charity, it doesn’t have to delete your data unless it specifically says it will. Charity Computer Aid promises to destroy any data on your old PC.

2. Think about how you store data
Avoid storing sensitive data (such as credit card numbers and passwords) on your PC. If you really need to store this data, encrypt it.

3. Use data deletion software
Our tests showed that paid-for packages such as TuneUp to be effective at obliterating data, so use one to remove your files before dumping your PC.

4. Destroy your drive
If you want to be sure that no one will ever access data on your hard drive, destroy it. Hit it with a hammer, drive a large nail through it, or smash it with an axe.

5. Don't worry!
If you’re careful, you significantly lower the chances of someone stealing your precious personal data.