Pirates who hijacked the Arctic Sea cargo ship earlier last month threatened to blow up the ship unless they were paid a ransom, according to Russian news agency Interfax.
The vessel was attacked by eight pirates from Latvia, Russia and Estonia on 24 July in Swedish territorial waters, according to Russian officials.
The report said that armed hijackers had surrendered their armament following an order by a Russian warship to halt the ship.
The Russian-owned cargo ship left a port in Finland on 24 July but contact with the vessel was reportedly lost shortly afterwards, sparking an international naval hunt on the high seas.
However, Maltese maritime authorities have claimed the vessel was never missing but was instead tracked from the moment of the hijacking until the Russian navy said it had reclaimed the ship.