Security analysts have raised privacy concerns over the ability of Apple’s iPhone to keep track of the owner’s movements.
The secret file contains the device’s time coded coordinates, which means anyone finding or stealing the phone could trace the owner’s movements or whereabouts.
For some there could be as much as one year’s worth of data on the phone.
The scientists who discovered the file say anyone – from a jealous spouse, a private detective or a stalker – with access to the phone or computer can obtain a detailed picture of the users lifestyle.
Researchers suggest only the iPhone has such an application.
Apple refused to comment on whether the file can be disabled or not.