Video: This is INS Kalvari, the Indian Navy's stealth weapon subjected to a massive data leak

In a major security breach, data running into more than 22,000 pages detailing the secret combat capabilities of Scorpene-class submarines that are being inducted into the Indian Navy have been leaked, an Australian publication reported on Tuesday.

The submarines are being built by French company DCNS and The Australian said the leak happened in France in 2011. Apart from sending shockwaves in the Indian defence establishment, it has also alarmed countries such as Malaysia, Chile and Brazil, which are either operating or have ordered a variant of the Scorpene, reports said.

India had signed a deal for six Scorpene-class submarines with the French firm in 2005 as part of its Project 75.

INS Kalvari, the first of the six submarines, successfully completed sea trials in May and is expected to be inducted into the Indian Navy by the end of this year. The submarines are being built at the government-owned Mazagaon Dock Shipbuilders Limited in Mumbai.

The video above, uploaded by Asian Defence, which also runs a blog on defence news, shows footage from INS Kalvari’s test run off the Mumbai coast.

The video below, uploaded by Indian Military Guide, outlines the features of the INS Kalvari. This will be the first new conventional submarine to be inducted into the Indian Navy in 16 years. However, its induction is now likely to be postponed, according to reports.

She has been named INS Kalvari after the feared tiger shark, a deep-sea predator. The submarine is said to have superior stealth features that allow it to go undetected in enemy waters for prolonged periods – the data leak also reportedly contains information about the Scorpene's secret stealth capabilities.

The delay in inducting the INS Kalvari will be a further setback to the Indian Navy that has only 14 submarines right now, against a required strength of 25-30. China, in comparison, has 68 submarines.