MOSCOW -- The final report into Russia's August 2000 Kursk submarine disaster said on Monday a torpedo fuel leak had caused the massive explosion which sank the nuclear-powered vessel with the loss of all 118 crew.

Ilya Klebanov, the senior government minister who headed the commission which compiled the report, said investigators had made their findings after key elements from the torpedo bay were raised from the bottom of the Barents Sea last month.

"A thermal explosion of components of the class 298A PV torpedo caused the disaster," Klebanov told Interfax news agency. "It happened as a result of a leak of hydrogen peroxide and the ignition of materials in the torpedo tube." Klebanov said the Kursk had been destroyed after a second explosion set off parts of the armaments stored in the first compartment of the Kursk, then Russia's most modern submarine.

Last month he cleared NATO and other foreign vessels of any role in the sinking of the Kursk, a suggestion the alliance had always denied, and dismissed a third theory that a World War II-era mine might have been responsible.

"All members of the government commission agreed with these conclusions," said Science and Technology Minister Klebanov. He added the conclusions would be handed to the prosecutor general, who is conducting a separate investigation.

It was not immediately clear what relatives of the dead crew made of the report, which has not yet been made available to the public and which newspapers say has been stamped "secret." Navy Chief Admiral Vladimir Kuroyedov said in February the model of torpedo used by the Kursk was being withdrawn.

Although no one has been held criminally responsible for Russia's worst naval disaster, President Vladimir Putin last December demoted three top navy commanders and sacked eight admirals in the Northern Fleet to which the Kursk belonged.

Senior military officials denied a direct link with the disaster but analysts noted the dismissals came hours after Putin received a preliminary report on the naval exercises during which the Kursk sank. It criticized "serious failures" in the fleet's military training.

The loss of the Kursk and the failure to rescue crew members who survived the initial blasts stunned Russia, leading to national soul-searching and an outpouring of grief.

It was also a low point of Vladimir Putin's young presidency, the Kremlin chief stung by a wave of criticism over his failure to cancel his holidays and lead the recovery operation in person.

Putin made it a point of honor to raise the wreck, an unprecedented recovery operation carried out last year. A total of 115 bodies were retrieved during two operations. The cost of the operation, including the dismantling of the 18,000 ton vessel, is expected to reach $130 million.

But not everyone is happy with the final Kursk report.