The construction of the Akula II class Nerpa nuclear attack submarine started in 1991 but has been suspended for over a decade due to lack of funding. Akula II class vessels are considered the quietest and deadliest of Russian nuclear-powered attack submarines.

"The submarine, built under a contract with the Russian Defense Ministry, has been moved from the shipyard in Komsomolsk-on-Amur to a maintenance facility in the Primorye Territory and fitted with all necessary equipment. At present it is undergoing sea trials," a spokesman for the shipyard told RIA Novosti.

Indian media have reported on various occasions that the construction of the submarine was partially financed by the Indian government. India has reportedly paid $650 million for a 10-year lease of the 12,000-ton submarine, said the agency.

The submarine 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.