The Russian navy has dismissed claims the Kursk was sunk by a missile from another Russian vessel.
Russian media has reported that the submarine was sunk by a cruise missile launched from the ship Peter the Great during a naval exercise.
All 118 men on board the Kursk submarine were killed in the Barents Sea last August.
Russian Navy chief spokesman Captain Igor Dygalo angrily dismissed the claim.
He said: "It's a pure invention which is not even worth a comment."
The government has not determined the cause of the disaster, saying it could have been triggered by an internal malfunction, a collision with a foreign submarine or a Second World War mine.
Most Russian and foreign experts believe that an exploding practice torpedo was the most probable cause.
Deputy Prime Minister Ilya Klebanov said the Cabinet would soon issue a formal order authorising a salvage mission. The Russian government is supposed to pay part of the mission's costs, estimated at £48 million, with the Kursk Foundation, an international fund-raising group based in Brussels, paying the rest.
Russian newspaper Segodnya reported that Russia's reluctance to provide its share - from one-third to one-half of the costs - has threatened to derail the entire project.
However Mr Klebanov's spokeswoman, Oksana Onishchenko, said: "The government order authorising the mission, which will be issued in about a week, will include the details of funding."
The plan envisages that the Kursk would be raised using cranes and towed to the Russian port of Murmansk under a giant barge. The operation is expected to be completed in August.