A post-mortem examination on Russian oligarch Boris Berezovsky has found he was hanged, police said.
The examination by a Home Office pathologist found nothing to indicate a violent struggle, a spokesman for Thames Valley Police said.
Further tests are now due to be carried out on the body of Mr Berezovsky, 67, who was found dead in his country home in Mill Lane, Ascot, Berkshire, on Saturday.
The results of the tests, including toxicology and histology examinations, were likely to take several weeks, police said.
Mr Berezovsky's body was moved from his home and forensic examination of the property is expected to take several days.
Police said they have found no evidence that anyone else was involved in his death, but there has been widespread speculation over what had happened.
Detective Chief Inspector Kevin Brown said: "Scenes of crime officers are carrying out further forensic examinations at the property and these are expected to last several days.
"A cordon will remain in place until this work has been completed, to protect the scene.
"While this important investigative work continues, we are unable to comment on any items found within the property.
"I would like to reiterate that we have no evidence of any third-party involvement at this stage."
Specialist officers in chemical, biological, radiological and nuclear substances examined the country pile on Sunday before declaring it safe.
The search was prompted when a radiation detector worn by the paramedic who pronounced the businessman dead was triggered on leaving the property.
The paramedic's detector, a personal electronic dosimeter (PED), is a health and safety device used routinely by emergency services.
An employee of Mr Berezovsky, believed to be the bodyguard, had called for the ambulance shortly after 3pm on Saturday after forcing open a bathroom door and finding the oligarch dead on the floor.
The employee had not not seen Mr Berezovsky since 10.30pm on Friday and had become concerned for his welfare, according to police.
Officers said they are speaking to the Russian's close friends and family to build up a picture of his state of mind in the last days of his life.
It is thought that he was having serious financial difficulties after paying out astronomical sums in legal fees over the last few years, and wanted to return to Russia.
The oligarch, who last year lost a multi-billion pound High Court battle with Chelsea FC owner Roman Abramovich, could have run up more than £100 million in legal bills since 2011.
In July of that year, he paid out Britain's biggest ever divorce settlement to ex-wife Galina Besharova.
Reports suggested the deal was worth more than £100 million.
And he later built up fees totalling more than £250,000 after becoming embroiled in a case at the High Court with his former partner Elena Gorbunova, who sat at his side throughout much of his battle with Mr Abramovich.
Mr Berezovsky emigrated to the UK in 2000 after falling out with Russian president Vladimir Putin.
In fear of his life, he sought political asylum in the UK and moved to the South East, buying upmarket properties in Knightsbridge, London, and Berkshire.
The businessman survived a number of assassination attempts, including a bomb in his car that decapitated his chauffeur.
He became a vocal and strong critic of Mr Putin's rule in Russia, where he had become a wanted man.
In 2006 the Kremlin accused foreign-based opponents of fatally poisoning former KGB spy-turned-dissident Alexander Litvinenko.
It was thought that Russia was in part referring to Mr Berezovsky, who denied the allegation and accused Mr Putin of personally being behind Mr Litvinenko's death from radioactive polonium-210 poisoning.
Berezovsky and Abramovich in 2000
n this Jan. 26, 2000 file photo Boris Berezovsky, left, a controversial business tycoon, and Roman Abramovich, Russian oil tycoon, with reported political connections, both parliament members, walk after the session of the State Duma, parliament's lower house, in Moscow, Russia. They were once said to be like father and son, vacationing, signing deals, and socializing at the Kremlin together. But these days two of Russia's richest men can't stand each other _
Russian oligarch and businessman Boris Berezovsky at his home in Egham, Surrey, where he lives in exile, 24th August 2002 (Photo by John Downing/Hulton Archive/Getty Images)
Russian Media Tycoon Boris Berezovsky
Russian media tycoon Boris Berezovsky says that he has film footage that proves that Russia's Federal Security Service (FSB) was behind a series of apartment block blasts in Moscow and the city of Volgodonsk in 1999 killing about 300 people creating a pretext for Russia's ongoing war in Chechnya. Russian officials dismissed Berezovsky's allegations and may issue charges and an arrest warrant accusing him of sending money to Chechen rebels. Berezovsky has evaded the charges by moving to London. (Photo by Borys Bierezowski/East News/Getty Images) (AMERICAS SALES ONLY)
Boris Berezovsky in 2002
Russian oligarch and businessman Boris Berezovsky outside his house in Egham, Surrey, where he lives in exile, 24th August 2002 (Photo by John Downing/Hulton Archive/Getty Images)
Boris Berezovsky Attends Extradition Hearing 2003
Russian business magnate and former Kremlin insider Boris Berezovsky wears a mask, showing the face of Russia's President Vladimir Putin, as he leaves Bow Street Magistrates Court April 2, 2003 in London. Berezovsky was arrested in Britain on March 24 after Russian officials sought his extradition on fraud charges. (Photo by Graeme Robertson/Getty Images)
(FILES) Picture dated November 1997, sho
MOSCOW, RUSSIAN FEDERATION: (FILES) Picture dated November 1997, shows Russian presidential candidate Ivan Rybkin (R) and Russian businessman Boris Berezovsky posing in Moscow. Rybkin, whose presidential campaign is financed by Boris Berezovsky, the controversial self-exiled tycoon and President Vladimir Putin's political foe, went missing after he left his apartment in Moscow 05 February 2004 and news of the 57-year-old's disappearance did not become public until the weekend. (FILM) AFP PHOTO / STR (Photo credit should read -/AFP/Getty Images)
Berezovsky protests imprisonment of Mikhail Khordorkovsky
Russian business man Boris Berezovsky stands in front of placards placed at the the Russian Consulate in London 26 May, 2004 calling for the release of his compatriot Mikhail Khodorkovsky. Berezovsky comissioned 100 limousines to drive past the Russian Consulate to demand the release of Khdorkovsky.
Member of the pro-Kremlin youth movement
Member of the pro-Kremlin youth movement Nashi (Ours) dressed as Russian business tycoon Boris Berezovsky poses in front of poster with a portrait of former boss of the Yukos oil company, Mikhail Khodorkovsky, in Moscow, 12 March 2007. A poster reading 'What is it, if not a treason'.
Extradition protests 2005
Supporters of Motherland (Rodina) party hold poster demanding the extradition of businessman Boris Berezovsky from London to Russia during a picket in front of the British embassy in Moscow, 01 March 2005. Berezovsky served as deputy of Russia's security council and was charged by former president Boris Yeltsin with negotiating relations with Chechnya in the late 1990s. After initially backing Vladimir Putin for the presidency in 2000, he had a falling out with the new Russian leader, eventually fleeing to Britain from prosecution for allegedly illegal business activity.
Young Guards Protest 2007
Picture of opposition leader and former Russian Prime Minister Mikhail Kasyanov and exiled Russian multi-millionaire Boris Berezovsky (reads 'Berezovsky, give us some money') lay in a dust container during a pro-Kremlin 'Young Guards of United Russia' movement rally in Moscow, 14 April 2007
An activist of the pro-Kremlin Young Guards of United Russia movement wears handcuffs and a mask of exiled Russian billionaire Boris Berezovsky during a protest rally in front of the headquarters of the Other Russia opposition movement in Moscow.
Marina Litvinenko and Boris Berezovsky
Marina Litvinenko and Boris Berezovsky at a news conference outside University College Hospital today on the first anniversary of the death of Alexander Litvinenko. Family and friends marked the murder of the outspoken Russian dissident by re-reading his deathbed statement, accusing President Vladimir Putin of complicity in the plot. See PA story POLICE Russia London.
Boris Berezhovsky Addresses Frontline Club Audience
Russian dissident-businessman Boris Berezhovsky is interviewed by BBC foreign correspondent Allan Little during his talk, Insight with Boris Berezovsky: Putting one over Putin, at the Frontline Club on June 6, 2007 in London, England. The controversial oligarch strained UK-Russian relations after recently claiming in an interview with The Guardian that he is scheming to topple Russian President Vladimir Putin. Berezovsky?s links to the poisoned Russian spy Alexander Litvinenko and his campaign against Putin, a man he once supported, have made him a wanted man in Russia. Berezhovsky was one of the Russian oligarchs who acquired massive wealth by taking control of state assets after the fall of communism. Russia has been demanding his extradition to face trial for several years. Britain so far has refused on the basis that he would not get a fair trial in his home country. (Photo by Daniel Berehulak/Getty Images)
Boris Berezovsky at a demonstration by Stategy 31 outside the Embassy of the Russian Federation, in Kensington, west London. Picture date: Tuesday, August 31, 2010. About 30 people waving placards attended the anti-Kremlin rally in central London which, unlike similar events in Moscow and St Petersburg, passed off peacefully.
An activist of the pro-Kremlin youth group Mestnye
An activist of the pro-Kremlin youth group Mestnye (Locals) carries a cage, containing a picture of Russian oligarch in British exile Boris Berezovsky, reading 'Jail the fraud!', during rally outside the British Embassy in Moscow on January 11, 2011 to support WikiLeaks founder Julian Assange.
Roman Abramovitch Takes The Stand As Boris Berezovsky Sues Him For Billions
Boris Berezovsky leaves The High Court with his partner Yelena Gorbunova on November 2011, where he alleged breach of trust and breach of contract over business deals with Chelsea Football Club owner Roman Abramovich and is claims more than £3.2bn in damages.
Russian billionaire Boris Berezovsky yacht "Thunder B" is seen in the harbor of Golfe Juan, southeastern France, Saturday, Feb. 19, 2011