A Surrey County police spokesperson told RIA Novosti Patarkatsishvili had complained of chest pains before he collapsed late on Tuesday at his country mansion in Leatherhead, 18 miles south of London.
The death of the 52 year-old Georgian prompted media to draw parallels with the radioactive poisoning of former Russian security officer Alexander Litvinenko in London in November 2006.
Police in Britain said on Wednesday that the death of Georgian billionaire was not linked to radioactive poisoning although it was initially treated as 'suspicious.' The toxicology tests are expected to take at least 10 weeks, the spokesperson added.
The tycoon body has not yet been handed over to relatives, who arrived in London Thursday. The businessman's close associate, Vano Chkhartishvili, said it was too early to talk about when the body would be transferred back to Tbilisi for burial.
"Everything depends on British experts," he added. Georgia's Rustavi 2 TV reported that the body could be flown back to Georgia on February 15.
Patarkatsishvili's personal doctor said that the businessman had never suffered any heart problems.
Representatives of Georgia's opposition said earlier they did not believe the British findings that Patarkatsishvili, who feared he was the target of an assassination plot, died 'of natural causes.'
"We do not believe the conclusion of Scotland Yard as even in the U.K. no one trusts Scotland Yard. We believe our own eyes and it would be better if independent experts were involved in cases like this," MP Kakha Kukava said.
Patarkatsishvili, Georgia's richest man, came third in the January 5 presidential polls in the ex-Soviet Caucasus state, garnering 7.1% of the vote. He was put on the wanted list at home on charges of plotting a coup during November 2007 street protests in Tbilisi against Georgian President Mikheil Saakashvili.
"The environment in which Patarkatsishvili lived - a violent confrontation with Georgia's leadership - could not but influence his health," editor-in-chief of the Novoe Russkoye Slovo newspaper, Sergei Gryzunov said.
Georgian MP Gocha Jojua, the tycoon's political associate, said Patarkatsishvili was "a victim of dirty political lies."
"What is the difference of how you kill a person - physically or by words," Jojua said.
In an interview with The Sunday Times in December, the tycoon said he feared he might be the target of an assassination plot. He referred to a tape recording allegedly containing a conversation between a Georgian interior ministry official and a Chechen warlord.
"Whoever planned to do this . . . we want to be able to explain to the people in Georgia that it was Russia," the alleged official tells the warlord during the recording.
The Georgian tycoon had himself faced a series of corruption charges, including in the case of Berezovsky's LogoVAZ group, of which Patarkatsishvili was a deputy general director.
The tycoon lived in Moscow for several years in the 1990s and was involved in the Russian media business. He was also the chairman of the Georgian soccer club Dynamo Tbilisi.
