The much-vaunted iTunes phone may disappoint, Forbes warned last night.

Citing sources, the report warns that the device, which has been jointly-developed by Apple and Motorola for the last year, may have a major fault - a 25-song limit on the number of tunes it's capable of carrying.

It appears that the phone will ship with limited memory, and that its built-in software will limit the number of available tracks to 25 - even if the flash memory module used is upgraded.

However, the report also warns that it's possible the model of iTunes phone seen by its sources will be different from the one that ships, or may also be only one of a series of handset models the company's plan.

Apple is widely-expected to launch the new device on September 7.