By Stephen Mulvey BBC News Online

Barayev, who was killed by Russian forces in June last year, was the most ruthless hostage-taker of Russians and Westerners in the breakaway republic, and may have had links with Osama Bin Laden.

Barayev was blamed for the deaths of four foreign workers in 1998

When four captive telecommunication workers - three Britons and one New Zealander - were beheaded in 1998, the responsibility lay at his door.

A fellow captive later told the BBC that he had been bidding for a $10m ransom from the men's employers, British Telecom and Surrey-based Granger Telecom, but he stood to get $20m more from "Arab friends" if he killed them.

According to Russian sources, these friends were none other than al-Qaeda.

The Barayev empire

When Arbi Barayev was killed after a six-day shootout with Russian soldiers in his home town of Alkhan-Kala last year, one of his nephews took over the remains of the Barayev empire.

At its height, this included a lucrative trade in Chechen oil, control of a main road through Chechnya and also hostage-taking.

Russian forces launched an operation to wipe out the nephew, named at the time as Movsan Suleimanov, in August 2001, and claimed to have killed him in Chechnya's second city of Argun.

It is not clear whether the man claiming to lead the operation in Moscow, whose name is Movsar Barayev, is the same nephew or a different one.

It would not be the first time that Russian forces have claimed falsely, or mistakenly, to have eliminated a rebel, who has later "risen from the dead".

Russian officials convinced sceptics of Arbi Barayev's death by parading his body on television.

Desperate

In past hostage-taking exploits, Chechen rebels have claimed their readiness to die for their cause, but have often then gone to great lengths to negotiate safe passage - with some of their hostages - back to Chechnya.

This time the rebels say they are suicide attackers, and it may just be true.

The Barayev clan are a desperate bunch.

Arbi is reported to have boasted that he had personally killed 170 people.