(AGI) - New Delhi, Aug 24 - Sensitive data related to India's ambitious Scorpene submarines has been leaked, with French shipbuilder DCNS which designed the submarine facing a leak of documents spreading over 22,000 pages, said an Australian media on Tuesday. The leak has come as a major blow to the Navy which is inching towards inducting its first diesel-electric attack submarine in nearly two decades after several delays. The total cost of the submarines is estimated to be US $3.75 billion. Indian Defence Ministry has ordered a probe into the leak of documents. The ministry also plans to investigate about who first obtained the confidential documents, which were made public by the Australian media. Indian Defence Minister Manohar Parrikar told media,"I understand there has been a case of hacking. We will find out what has happened." According to the report, DCNS has said that such a leak of technical data could not happen with its proposed submarine for Australia. The DCNS also implied that the leak might have occurred at India's end, rather than from France. "Uncontrolled technical data is not possible in the Australian Aarrangements," the company said as per the report in Australian media. In October 2005, India placed an order for six Scorpene-class attack submarines. Currently, the submarines are being built at the Mazagon dockyard in Mumbai, with technical help and equipment from French companies DCN and Thales. Construction of the first Scorpene submarine began in December 2006. (AGI) .