The 23-year-old leader of the Moscow hostage-takers is the nephew of a Chechen warlord reportedly paid £20m by Osama bin Laden to execute four engineers.

Three British telephone engineers were murdered in 1998 by allies of Osama bin Laden, a BBC programme will say this week.

Prominent Chechen warlord, Arbi Barayev, was killed in an operation by Russian troops who had blockaded a central Chechen town for days to search for him and other rebel fighters, officials said today.