Moscow, Feb 26 (IANS) Two Russian mini-subs that have spent the past two summers researching Siberia's Lake Baikal will return to the depths of the world's deepest freshwater lake this summer, a senior researcher said.

Anatoly Sagalevich of Russia's Shirshov Institute of Oceanology said that Russia's Mir-1 and Mir-2 mini-subs would also join an international scientific project in the Atlantic this year and would probably dive to the Titanic.

'The mini-subs are currently being stored near Lake Baikal and will start their work in the summer,' Sagalevich said.

A source in the Institute of Oceanology earlier told RIA Novosti that the Akademik Mstislav Keldysh research vessel, which carries the mini-subs, is currently in German waters and plans to do research in the Barents Sea this summer.

The expedition to Lake Baikal started in 2008. Last summer, researchers sought new species of flora and fauna, and dove down more than a mile (1.6 km) to the deepest point of the lake, near Olkhon Island.

Mir-1 and Mir-2 worked in the southern part of the lake, and in August 2009 the expedition moved to Baikal's north, where gas hydrates, crystalline solids, and large amounts of methane trapped within a cage of water molecules, were found. Gas hydrates are considered a possible alternative fuel.

Russian Prime Minister Vladimir Putin made a 4-hour dive in the Mir-1 mini-submarine to the bottom of Lake Baikal in August last year.

The total cost of the expedition was $8 million, with a single dive costing 2 million rubles ($64,800).