A multi-billion-dollar court fight involving Chelsea football club owner Roman Abramovich, and his former business partner Boris Berezovsky, is underway in London.

Berezovsky has accused Abramovich of using political intimidation to force him to sell Russia's fourth-biggest oil firm at a knockdown price.

Abramovich, the world's 68th richest man, with an estimated fortune of $12bn, denies the charges and says he merely paid Berezovsky money for political cover and protection.

Al Jazeera’s Nadim Baba reports.