Mr Klebanov was deputy prime minister for Russia's military-industrial complex, but now will have only his second post of minister for industry, science and technology.

The submarine sank after explosions in its bow.

The announcement comes on the same day Prosecutor-General Vladimir Ustinov declared that the examination of the wreck of the Kursk had been completed, and that the evidence uncovered would go towards a criminal case against those responsible for the loss of the submarine.

No-one is blaming Mr Klebanov for the loss of the Kursk.

But he is certainly associated with much of the poor handling of information in the wake of the disaster in August 2000 - including the now-abandoned suggestion that the submarine sank after being struck by a foreign vessel.

Heads roll

Mr Klebanov's demotion seems to be part of a wider reckoning against those involved with the Russian navy's worst submarine accident.

Investigators have been picking their way carefully through the wreck of the Kursk for nearly four months.

The navy's initial handling of the disaster outraged relatives

Last autumn, the vessel - minus the nose, which was most badly damaged by two on-board explosions - was brought to the surface of the Barents Sea and put in dry dock.

As well as recovering 94 of the bodies of the 118-strong crew, investigators have removed data recorders, log-books and other documentation.

On the strength of this, they say it is clear that the Kursk was sunk by an explosion of one its own torpedoes.

The torpedoes had a hydrogen peroxide fuel charge, which other navies have long refused to use because of its inherent instability.

The Russian navy's commander, Admiral Vladimir Kuroyedov, announced on Monday that the volatile torpedoes had now been withdrawn from service.

But the prosecutor-general is suggesting that other factors, such as what he has described as the navy's "traditional sloppiness", were also responsible.

The Head of the Northern Fleet Admiral Vladimir Popov and other senior officers have already been sacked.

But Mr Ustinov's tone suggests that the consequences of the Kursk tragedy will be far-reaching.