Pioneer is developing a Blu-ray disc that has capacity for around 8 high def movies and related extras.

The super multi-layer optical disc has 16 seperate layers on each side, with each layer boasting 25GB storage capacity.

This compares to today's Blu-ray discs that offer up to 50GB capacity on a double layer - around ten times that of a DVD.

The technology that allows such a high storage capacity is due to a breakthrough in the reflective layers material, Pioneer says.

Crucially, the 400GB discs would play on "ordinary" Blu-ray players and drives, so do not need special equipment.

Pioneer plans to launch the read-only new capacity discs before 2010, then will develop rewritable versions before 2012 and boasts it will offer a 1TB disc in 2013.