British police say their initial investigation has not turned up any evidence suggesting “third-party involvement” in the death of Boris Berezovsky.
The police statement issued on March 24 comes after experts in chemical, biological, and nuclear materials searched the self-exiled Russian tycoon’s home in Ascot, west of London, where his body was found the previous day.
According to police, the specialists’ examination had found “nothing of concern.” An earlier statement said searches by the experts were being carried out as a “precaution” to protect officers investigating the death.
Police have previously described Berezovsky’s death as “unexplained.”
According to the authorities, an employee of Berezovsky said he called an ambulance on March 24 after becoming concerned for the former oligarch's welfare.
They said the employee told police he forced open a locked bathroom door and discovered Berezovsky's body on the floor.
Berezovsky was pronounced dead by a paramedic.
Police told reporters on March 24 that it would be wrong to speculate on the cause of death until an autopsy is completed.
Russia’s embassy in London says it will issue a statement on March 25 about Berezovsky’s death.
Berezovsky, 67, a prominent critic of President Vladimir Putin, was found dead on March 23. British media reported he was found dead in his bath.
Berezovsky's friend and fellow Kremlin critic, the ex-KGB agent Aleksandr 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 ever to return to Russia.
Zhegulev said it had been an informal interview given by Berezovsky on March 22 and had not been recorded.
With reporting by Interfax, RT, BBC, and telegraph.co.uk