British police say experts in chemical, biological, and nuclear emergencies have been deployed to the home where Russian exile and Kremlin critic Boris Berezovsky was found dead.
A statement said searches by the experts were being carried out as a “precaution” to protect officers investigating the death.
It added that Berezovsky’s body remains at his home near Ascot, close to London.
Police earlier described Berezovsky’s death as “unexplained.”
Berezovsky, 67, a prominent critic of President Vladimir Putin, was found dead Saturday. British media reported he was found dead in his bath.
Berezovsky’s friend and fellow Kremlin critic, the ex-KGB agent Alexander Litvinenko, was killed by radioactive poisoning in London in 2006.
Litvinenko’s widow has called the death an assassination by Russian agents. This has been denied by Moscow.
Berezovsky had been prominent among the group of Russian businessmen known as the oligarchs who grew rich from the privatization of state assets following the collapse of Soviet communism.
Berezovsky made his fortune in the early 1990s by selling cars. He then moved into oil, buying the Sibneft oil company. He also built a media empire.
He survived several assassination attempts, including one that decapitated his driver in the early 1990s.
Berezovsky was an influential Kremlin insider under former Russian President Boris Yeltsin, whose reelection he supported in 1996.
Berezovsky helped current Russian President Vladimir Putin’s rise to succeed Yeltsin in 2000.
But when Putin moved to curb the political powers of the oligarchs, Berezovsky left Russia for self-imposed exile in Britain, where he was granted political asylum in 2003.
From London, he became one of Putin’s most outspoken critics. The harsh words he used in a 2007 interview were typical of his rhetoric from exile.
“Putin’s Russia is very dangerous for democracy, not only inside of Russia, but also outside of Russia. It means that Russia is very dangerous for the West and I think the sooner the West recognizes that Russia is not an ally, that Russia is not a partner — I mean Putin’s Russia — this will help the West more quickly find the tools to protect themselves,” Berezovsky said.
Berezovsky was a wanted man in Russia where he had been convicted and sentenced to jail in absentia on embezzlement charges.
Last year, he lost a bitter and expensive legal battle in London against fellow Russian tycoon and Chelsea Football Club owner Roman Abramovich.
Berezovsky’s wealth is thought to have considerably diminished in recent years.
Kremlin spokesman Dmitry Peskov told Russian state television on March 23 that Berezovsky had recenty asked Putin for “forgiveness for his mistakes” and for help to return to Russia.
Peskov said that “some time ago, maybe a couple of months ago” Berezovsky had sent Putin a letter. He said he did not know how Putin had reacted to Berezovsky’s letter.
He said Putin “had been informed” of Berezovsky’s death.
The Russian-language website of “Forbes” magazine has published what was described as Berezovksy’s last interview.
Berezovsky is quoted by journalist Ilya Zhegulev as saying his “life no longer makes sense” and that he wanted more than to return to Russia.
Zhegulev said it had been an informal interview given by Berezovsky on Friday evening and had not been recorded.