French shipbuilder DCNS has been hit by a massive data leak affecting a major submarine contract for the Indian navy.
The leak of more than 22,000 pages exposes detailed information about the combat capability of the Scorpene class vessels.
It is not clear who first obtained the confidential documents, which were made public by the Australian media.
Earlier this year DCNS won Australia's largest-ever defence contract to build a fleet of advanced submarines.
Details about the Shortfin Barracuda submarine class that will be built for Australia were not contained in the leak.