Australian Defense: Our French submarine builder in massive leak scandal, by Cameron Stewart.

The French company that won the bid to design Australia’s new $50 billion submarine fleet has suffered a massive leak of secret documents, raising fears about the future security of top-secret data on the navy’s future fleet.

The stunning leak, which runs to 22,400 pages and has been seen by The Australian, details the ­entire secret combat capability of the six Scorpene-class submarines that French shipbuilder DCNS has designed for the Indian Navy.

Indian Scorpene submarine on the day of her undocking, in 2015

In April DCNS, which is two-thirds owned by the French government, won the hotly contested bid over Germany and Japan to design 12 new submarines for Australia. Its proposed submarine for Australia — the yet-to-be-built Shortfin Barracuda — was chosen ahead of its rivals because it was considered to be the quietest in the water, making it perfectly suited to intelligence-gathering operations against China and others in the ­region.

Any stealth advantage for the navy’s new submarines would be gravely compromised if data on its planned combat and performance capabilities was leaked in the same manner as the data from the ­Scorpene.

The leaked DCNS data details the secret stealth capabilities of the six new Indian submarines, including what frequencies they gather intelligence at, what levels of noise they make at various speeds and their diving depths, range and endurance — all sensitive information that is highly classified.

Maybe the French will not keep the secrets about our boats too? Maybe the Americans will be reluctant to let us use their submarine combat systems, as planned, if they fear the French might leak them.

[T]he data on the Scorpene was written in France for India in 2011 and is suspected of being removed from France in that same year by a former French Navy officer who was at that time a DCNS subcontractor.