By Daniel Arkin, Staff Writer, NBC News
British police said evidence at the home of Boris Berezovsky, an exiled Russian oligarch who was found dead near London on Saturday, does not indicate "third party involvement."
?It would be wrong to speculate on the cause of death until the post mortem has been carried out. We do not have evidence at this stage to suggest third party involvement,? Detective Chief Inspector Kevin Brown, Deputy Senior Investigating Officer in the case, said in a statement.
Berezovsky, 67, amassed a mammoth fortune as an oil and automobiles magnate during Russia?s post-Soviet privatization of state assets in the early 1990s. He also accrued immense political influence, catapulting Boris Yeltsin to re-election in?1996 and brokering Vladimir Putin?s rise to prominence.
But when Putin became president of Russia in 2000, Berezovsky became one of his harshest critics and?often clashed?with the Kremlin. He soon fled to Britain, where he was granted political asylum three years later.
Police said the tycoon?s death was ?unexplained? and are working to make sense of Berezovksy?s final hours.
?The investigation team (is) building a picture of the last days of Mr. Berezovsky?s life, speaking to close friends and family to gain a better understanding of his state of mind,? said Brown.
Authorities announced Sunday that radioactive, biological and chemical specialists sent to conduct tests gave the scene an ?all clear,? The Associated Press reported.
?Officials found nothing of concern in the property, and we are now progressing the investigation as normal,? according to the police statement.
Heightening the intrigue is the fact that Berezovsky was a close friend of Alexander Litvinenko, a Russian dissident who was fatally and mysteriously poisoned with radioactive polonium in London in 2006.
Berezovsky was an outspoken opponent of Putin in recent years, charging the president with dictatorial policies and domestic terrorism. Berezovsky, who survived assassination attempts ? including a bombing that decapitated his driver ? said he feared retributive violence after criticizing the government, according to Reuters.
A spokesman for Putin on the Russia 24 television station said that he was not aware of the president?s reaction to the news of Berezovsky?s death, but that ?news of anyone?s death, no matter what kind of person they were, cannot arouse any positive emotions.?
NBC News? Becky Bratu contributed to this report.