Sydney, Documents detailing the secret combat capabilities of Scorpene-class submarines that French shipbuilder DCNS has designed for the Indian Navy have been leaked.

The data, reportedly running into over 22, 000 pages, has been marked ‘Restricted Scorpene India’.

Australia awarded DCNS an Aus $50 billion (US$38 billion) contract last April to design and build its next generation of submarines.

According to the sources, the sensitive leak includes details of the submarine’s underwater sensors, above-water sensors, combat management system, torpedo launch system and specifications, communications system and navigation systems.