MOSCOW, April 5. /TASS/. The work to repair the AS-31 nuclear-powered submersible, damaged in deadly fire on July 1, 2019, may take up to four years, a source in the Russian military industrial complex told TASS on Monday.

"Repair works of the Losharik submersible may take up to four years," the source said. "The submersible will be then returned to its combat duty."

The press office of the Sevmash Shipyard (part of the United Shipbuilding Corporation), where the submersible is planned to undergo repairs, refrained from commenting on the information provided by the source.

The fire on the AS-31 military research submersible broke out on July 1, killing 14 submarine officers. Four of them were posthumously bestowed with the Hero of Russia title and the other ten with the Order of Courage.

An explosion and a faulty lithium battery were named among the likely causes of the incident. In early November, the submersible was delivered to the Zvyozdochka Shipyard in Severodvinsk in the northern Arkhangelsk Region. Losharik was towed to the facility for repairs in the fall of 2019.

The Project No. and the performance characteristics of the AS-31 first-rank nuclear-powered submersible station have not been disclosed. The available data indicates that the submersible carries no armament and can dive to big depths. The submarine severely damaged by the fire in the Barents Sea was nicknamed the Losharik due to the hull’s specific shape in the form of several connected titanium spheres.