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While companies such as TDK and Panasonic have previously mooted 100GB discs, they have always needed a specially developed optical head in the player to read the disc.

Hitachi, however, claims to have used a standard Blu-Ray drive optical head that's only slightly modified to allow it to read and write data across the four 25GB layers. It's believed this will only require a firmware update to make existing drives compatible.

The company is apparently working now to stabilise signal quality before considering a commercial roll-out.

The hardware manufacturer is also researching an eight layer disc that can hold 200GB of data but has encountered problems with reflections decreasing signal strength across the eight layers, which it is working to rectify.

At the time of going to press there is no word on when the disc will be ready for commercial release.