Financed partly by India under a secret deal signed with Russia in January 2004, the 12,000-ton Akula-II class nuclear-powered attack submarine has been built at the Komsomolsk-on-Amur shipyard in Russia, and will be commissioned with the Indian navy as INS Chakra.
"The submarine's sea-based trials will follow after that," Times of India quoted an anonymous Indian defense source as saying. "We expect the submarine to join the Indian navy in the second half of 2009."
Akula II class vessels are considered the quietest and deadliest among Russian nuclear-powered attack submarines.
According to various reports, India is currently building three domestically-designed nuclear submarines under a top-secret Advanced Technology Vessel (ATV) program but needs to give its navy first-hand experience in nuclear submarine operations, deployment and maintenance prior to the deployment of domestic submarines.
"Our sailors... have been undergoing training in Russia to operate INS Chakra for the last two-three years. Once we get it, it will be the ideal platform to train future crews for the ATVs," the Indian source said.
The nuclear submarine leased by Russia will not be equipped with long-range cruise missiles due to international restrictions on missile technology proliferation, but India may later opt to fit it with domestically designed long-range nuclear-capable missiles.
At present, India operates 16 conventional diesel submarines and awaits six French-Spanish Scorpene class diesel attack submarines, to be delivered between 2012 and 2017, but plans to deploy at least three nuclear submarines armed with long-range strategic missiles by 2015.
The first of the three domestic nuclear submarines is expected to begin sea trials by mid-2009.
India previously leased a Charlie-I class nuclear submarine from the Soviet Union from 1988 to 1991.