Boris Berezovsky death: Chemical hazard police search house
A cordon remains in place around Boris Berezovsky's house
Police with expertise in environments contaminated with chemical, biological and nuclear material are searching the house of the late exiled Russian tycoon Boris Berezovsky.
Mr Berezovsky, 67, was found dead on Saturday, and a Thames Valley police cordon remains in place as police investigate his unexplained death.The body remains at the Berkshire house while the search - described as a precaution - takes place, police said.They say local people are not at risk.
The ambulance service was called to the Ascot house of Mr Berezovsky at 15:18 GMT on Saturday. His body was reportedly found in a bath.
A Thames Valley police update said: "Specially trained officers are currently at the scene, including CBRN [chemical, biological, radiological, and nuclear] trained officers, who are conducting a number of searches as a precaution.
"This is to enable officers to carry out an investigation into the man's death."
Boris Berezovsky led a colourful and controversial life
Supt Stuart Greenfield said: "We are aware the cordon is causing disruption to local residents and we apologise for any inconvenience, but it is important we take all necessary measures to ensure a full and thorough investigation can be carried out.
"I would like to reassure residents that we are confident there is no risk to the wider community."
He said the property was part of a large estate, so a number of roads were closed "and will remain so for the time being".
A former Kremlin power-broker whose fortunes declined under President Vladimir Putin, Mr Berezovsky emigrated to the UK in 2000.
He was a wanted man in Russia, an opponent of Mr Putin, and had survived numerous assassination attempts, including a bomb that decapitated his chauffeur.
Mr Berezovsky was a close friend of murdered Russian emigre and former KGB officer Alexander Litvinenko, who died in 2006 after he was poisoned with the radioactive material polonium-210 while drinking tea at a London meeting.
Alexander Litvinenko was a close associate of Mr Berezovsky
Without naming Mr Berezovsky, the Kremlin has accused its foreign-based opponents of organising the assassination - a claim Mr Berezovsky denied. He accused Mr Putin of being behind the death.
BBC diplomatic correspondent Bridget Kendall said an interview Mr Berezovsky gave on the eve of his death might shed some light on his state of mind.
In the interview with a journalist from Forbes magazine on Friday, Mr Berezovsky said that he had changed his mind on many things, his life no longer made sense and he wished he could return to Russia.
Last night a Kremlin spokesman said that Mr Berezovsky had recently written to Mr Putin, saying he wanted to go home.
The tycoon's wealth is thought to have considerably diminished in recent years, leaving him struggling to pay debts in the wake of costly court cases.
Last year, Mr Berezovsky lost a £3bn ($4.7bn) damages claim against Chelsea Football Club owner Roman Abramovich.
Obituary: Boris Berezovsky
Mr Berezovsky lived in exile in the UK since 2000
Russian dissident Boris Berezovsky was a former Kremlin power broker whose fortunes went into dramatic decline as Vladimir Putin established himself as Russian president.Mr Berezovsky himself played a role in Mr Putin's rise in the late 1990s, but went into opposition and then self-imposed exile in the UK as the new president consolidated his power.
He remained a wanted man in Russia until his death, and was for a long time dedicated to the anti-Putin cause.In recent years, his wealth is thought to have considerably diminished and recent court cases have left him struggling to pay legal fees and other debts.
In 2012 a court battle in London with fellow "oligarch" Roman Abramovich, his former associate with whom he fell out as Mr Putin came to power, ended in defeat, with his allegations that he was intimidated by Mr Abramovich into selling shares in Russian oil giant Sibneft for a "fraction of their true worth" entirely rejected by the judge.
Sources told the BBC that he had been depressed after losing the case, and moved suddenly out of his offices in central London.
And earlier this year, his ex-partner Yelena Gorbunova alleged in the High Court that he owed her millions of pounds from the sale of a £25m property in Surrey.
On 18 March The Times newspaper reported that Mr Berezovsky had been forced to try to sell a painting by Andy Warhol of the former Soviet leader Vladimir Lenin.
The role of political plotter, and financier of Russian opposition parties, was the latest in a series of reincarnations that Mr Berezovsky went through in his 67 years.
His first career was as a mathematician, his second as a car salesman, his third as a political kingmaker, nicknamed Rasputin, under Russia's first president Boris Yeltsin.
“I understood [then] that this way of open opposition doesn't work, at least for me - and that's the reason why I decided to choose the other way” End Quote Boris Berezovsky
Mr Berezovsky made his fortune importing Mercedes cars into Russia in the 1990s, and setting himself up as a middleman distributing cars made by Russia's Avtovaz.
While Avtovaz struggled to survive, Mr Berezovsky nevertheless made millions.By the mid-1990s, he was one of Russia's leading oligarchs, a word used for those who made their fortunes during the wholesale privatisation of state assets.As well as taking ownership of the Sibneft oil company, he became the main shareholder in the country's main television channel, ORT, which he turned into a propaganda vehicle for Boris Yeltsin in the run-up to the 1996 presidential election.
He has survived numerous assassination attempts, including a bomb that decapitated his chauffeur.He took Forbes magazine to court for describing him as the "godfather of the Kremlin" and linking him to the murder of a popular television journalist.Forbes settled out of court, accepting that the allegations were false.
Mr Berezovsky was at the height of his power in the later Yeltsin years, when he was deputy secretary of Russia's security council, a friend of Boris Yeltsin's daughter Tatyana, and a member of the Yeltsin inner circle, or "family".
Although he helped Mr Putin enter the family, and funded the party that formed Mr Putin's parliamentary base, the new president moved to regain control of the ORT television station, and to curb the political ambitions of Russia's oligarchs.
Mr Berezovsky left Russia for self-imposed exile in the UK at the end of 2000.
An early attempt to promote opposition to Mr Putin, by funding the Liberal Russia party, ended in disaster when its two most prominent members were assassinated.
"I understood [then] that this way of open opposition doesn't work, at least for me. And that's the reason why I decided to choose the other way," he later said.
Without naming Mr Berezovsky, the Kremlin accused its foreign-based opponents of organising the 2006 assassinations of former KGB agent Alexander Litvinenko and the campaigning journalist Anna Politkovskaya, in order to discredit Mr Putin.Mr Berezovsky denied the allegation, and accused Mr Putin of himself being behind Litvinenko's death.
Mr Berezovsky bought the ex-spy - himself in exile in London - a house in Muswell Hill and helped him to publicise claims that Mr Putin organised the bombings of apartment blocks in Russia, in 1999, which paved the way for Russia's second military intervention in Chechnya.He said Mr Putin was prepared to kill anyone that he defined as an enemy of Russia, and that he himself was a target.
That is why the mansion he bought for £10m from former disc jockey Chris Evans was equipped with bullet-proof windows, laser monitors, spy cameras and reinforced steel doors.