iOS 5 is being tested internally at Apple, according to a developer, who cited a crash report as confirmation of the claim.

According to Apple Insider, developer FutureTap posted on Twitter: "Just received the first iOS 5.0 crash report. MKUserLocationBreadCrumb sounds interesting."

FutureTap also posted a screengrab of the report, which seems to indicate Apple is testing iOS 5 internally using third-party apps.

The reference to "MKUserLocationBreadCrumb" is significant as it relates to the location of an iOS device and its changes over time.

In its response to an outcry over the storage of location data in iOS devices, Apple yesterday conceded that it was "collecting anonymous traffic data to build a crowd-sourced traffic database with the goal of providing iPhone users an improved traffic service in the next couple of years", suggesting that it was working on its own satnav system for iOS.

MKUserLocation has been present in iOS since version 3. iOS 5 is expected to launch with the fifth-generation iPhone, though whether this will happen in June or September this year is unclear.