The latest software update for iPhone 6 handsets is allegedly rendering the devices useless if it detects repairs not carried out by Apple. The problem is known as "error 53" and has appeared in Apple products before. The Guardian reports that users' phones were disabled after the Touch ID home button was repaired by a non-Apple engineer. The issue appears to arise once devices have been updated to the latest operating system, iOS 9. In its report, the Guardian cites the experiences of a freelance photographer, Antonio Olmos, who says the problem occurred on his phone after he upgraded its software.

At Apple's discussion forums, one user named wallihall wrote: "With this update I'm unable to use the phone, and still have to pay for the phone itself. "I did get the front screen replaced, and I understand that it's now considered "tampered with", but at least let me use my iPhone on the old IOS system... I can't retrieve old photos or important documents I once had." Apple told the paper that iPhone software checks whether any repairs were authorised by Apple. A spokeswoman said: "When an iPhone is serviced by an unauthorised repair provider, faulty screens or other invalid components that affect the touch ID sensor could cause the check to fail if the pairing cannot be validated. "With a subsequent update or restore, additional security checks result in an 'error 53' being displayed."