Iphone collects and stores location information even when location services are turned off.

By JENNIFER VALENTINO-DEVRIES. The Wall Street Journal.

Apple Inc.'s iPhone is collecting and storing location information even when location services are turned off, according to a test conducted by The Wall Street Journal.

The location data appear to be collected using cellphone towers and Wi-Fi access points near a user's phone and don't appear to be transmitted back to Apple. Apple didn't immediately respond to a request for comment.

Still, the fact that the iPhone is collecting and storing location data—even when location services are turned off—is likely to renew questions about how well users are informed about the data being gathered by their cellphones. The fact that the iPhone stores months' worth of location data was disclosed by two researchers last week.

The discovery of an unencrypted location file on the iPhone created an uproar among people concerned that their phones could be searched and their location data used against them. On Saturday, Rep. Edward Markey (D., Mass.) called for a congressional investigation into the iPhone location storage, saying that unprotected location information on the phone could put children at risk from predators who hack their phones.

The discovery of the iPhone location file comes amid growing concern about cellphone tracking overall.

Last week, the Journal reported that Apple's iPhone and cellphones powered by Google Inc.'s Android software transmitted their locations back to Google and Apple, respectively.

And last year, a Journal investigation showed that many of the most popular cellphone "apps" go even further, sharing location data and other personal information with third-party companies without a user's knowledge or consent.

Apple and Google have both previously said that the data they receive is anonymous and that users can turn it off by disabling location services.

However, it appears that turning off location services doesn't disable the storage of location data on iPhones. The Journal tested the collection of data on an iPhone 4 that had been restored to factory settings and was running the latest version of Apple's iOS operating system.

The Journal disabled location services (which are on by default) and immediately recorded the data that had initially been gathered by the phone. The Journal then carried the phone to new locations and observed the data. Over the span of several hours as the phone was moved, it continued to collect location data from new places.

These data included coordinates and time stamps; however, the coordinates were not from the exact locations that the phone traveled, and some of them were several miles away. The phone also didn't indicate how much time was spent in a given location. Other technology watchers on blogs and message boards online have recorded similar findings.