Apple is accused of unwittingly encouraging phone theft after it emerged the company does not check if a broken iPhone has been stolen before issuing a replacement handset.

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Anyone can take a used handset into the firm's "Genius Bar" repairs service, and if it is locked or broken beyond repair, a replacement phone can be issued under warranty. Apple employees do not check whether the person bringing in the iPhone is the legal owner, and do not check it against the police-approved database of lost and stolen phones.

David Hanson, the Labour MP who helped set up the database, said: "This is a crime prevention tool they should use, and in my view they will be negligent if they don't. They are contributing to a loophole which will encourage people to steal mobile phones for cash or exchange."

iPhones make up around 14 per cent of the total number of mobiles in the UK. But figures obtained by Channel 4 News show they account for 28 per cent of the two million phones lost or stolen each year.

Five tips to avoid becoming an iPhone crime victim:
Keep looking up and around - if you're absorbed in your mobile screen, you're an easy target.
Install findmyiphone or another tracking app - this can help police trace your phone.
If you get mugged, call 999 immediately - the minutes after a theft are vital for police to find the perpetrators.
Register your phone on http://www.immobilise.com/ - if it's stolen, you can mark it as such.
Put a passcode lock on your iPhone - and also lock the settings so a thief can't disable the GPS and hinder tracking (there is advice on the Apple website).

Charlie Durrant was a victim of iPhone theft. After her handset was stolen last year she reported the theft to Apple and her insurer. However, when she requested a replacement phone, her insurer told her that one had already been issued in her name. The thief had taken advantage of Apple's lack of checks.

She said: "I phoned Apple up and they said 'Yes, we've replaced it', and they gave me the name of the shop and the name of the person who'd helped them, and the time and the date. Three days after my iPhone had been stolen someone had just gone in and got a brand new one, making my insurance invalid. I just found it unbelievable that they could do that."

Channel 4 News joined Camden Police's robbery squad as they patrolled North London. Ninety per cent of the unit's time is spent on mobile phone theft, and iPhones are the prime target. Some robbers will ignore bags and wallets in favour of Apple's most popular product.

Read more: Why does a secret iPhone file track your movements?

The unit's PC Paul McAuslan said: "They're the most popular because they get the most money for them when they sell them, and they can be sold on certain auction sites, or sold as spares."

Pawnbrokers such as Cash Converters and CeX check all phones brought into them against a system called CheckMEND, which contains details of 50 billion items. Each phone has a unique number, called the IMEI, and if the phone has been reported lost or stolen, the CheckMEND system will instantly inform the shop, which will refuse to buy the phone.

Apple has declined to comment.

You can follow Geoff White on Twitter @geoffwhite247