Sources in the naval headquarters, where the documents are being analysed, however said that the documents are old and that it has not yet been established how relevant the leaked information is.
The documents have a section dealing with noise generated during patrol, attack and snorting (staying submerged but taking in surface air through the snorkel) modes.
Noise is a critical component in detecting a submarine.
Tracking a submarine involves sophisticated sonar equipment that can detect, classify, locate and track a vessel based on echoes from its hull and the noise it generates.
Hull reflection, radio and radar signals and water pressure can also give away a submarine's location.
To this extent, the Scorpene's stealth characteristic is its biggest strength. This has been acheived by modifying its hull and reducing its noise footprint.
One of the leaked documents is dated January 15, 2011 and is flagged "Restricted Scorpene India".
This deals with the submarine's environmental parameters and operational characteristics, including its transmission frequency.
These details, if found relevant, may compromise the Scorpene, which the Indian Navy had been looking to form the core of its submarine arm for the next two decades.
The documents published by the Australian media are, however, blurred on the exact parameters.
