Russian businessman Boris Berezovsky has died at the age of 67.
The exiled businessman, who last year lost a multibillion-pound High Court case with Chelsea Football Club owner Roman Abramovich, was found dead at his home in Berkshire, England.
Lord Tim Bell, the advertising and PR executive, confirmed his death.
A spokesman for his company, Bell Pottinger, said Mr Berezovsky was found at his home in Ascot, Berkshire.
"His body was found by his bodyguard," he said. "No other details are available at this time."
Mr 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.
Mr Berezovsky emigrated to the UK in 2000 after falling out with President Vladimir Putin.
In fear of his life, he sought political asylum and moved to the southeast of England, buying upmarket properties in Knightsbridge and Berkshire.
