Berezovsky was part of Boris Yeltsin's inner circle in the latter years of his presidency, and became deputy secretary of Russia's security council.
He acquired his fortune in the 1990s after the privatisation of state assets following the collapse of Soviet Communism.
The businessman survived a number of assassination attempts, including a bomb in his car that decapitated his chauffeur.
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A man accused of murdering his father says he lost control after a lifetime of being bullied by him.
Tuesday night's weather for the east of the region
Tuesday night's weather for the west of the region