Businessman Boris Berezovsky took on Chelsea football club owner Roman Abramovich in a case worth billions.

The case hinged on a labyrinthine web of deals made following the collapse of communism and the privatisation of former Soviet state assets in the 1990s.

Mr Berezovsky, once one of the most powerful of Russia’s oligarchs, said he was forced to flee Russia in 2000 because of a row with the then president Vladimir Putin.

An exclusive preview of the biggest case in the UK courts is published here.