A hacking group calling itself the 'Paradogs' has broken the copyright protection on Sony's Playstation Portable.

The group succeeded in extracting the files from the Universal Media Disc (UMD), a proprietary storage module that contains games or movies for the Sony gaming device.

The ability to extract files from the discs is a first step in producing illegal copies of the software or making adjustments to the code.

Because there are no UMD burners available, the crack will not cause much harm for now. But users could in theory put the software on a memory stick and run it from the storage device.

The Paradogs specialise in removing copyright protection from video games for a range of platforms such as PCs and Sony's Playstation. The group also creates 'cheats' that give players infinite lives or resources.

The Playstation Portable has been on sale in Japan since last year, and was launched in the US on 24 March. It is slated for release in Europe on 1 September.

The device uses the UMD format to store games and movies. Developing the disc was the only way for Sony to create a storage medium that was cheap to produce and small enough to fit into the device.