An exiled Georgian billionaire who had spoken of assassination fears died of natural causes, according to initial post-mortem tests, Surrey police said.
Mr Patarkatsishvili had expressed assassination fears
Police were treating the death of Badri Patarkatsishvili, 52, as "suspicious", which is standard with sudden deaths.
Toxicology tests are yet to be carried out on the tycoon, who died on Tuesday at his mansion in Leatherhead, Surrey.
He was charged with plotting a coup in Georgia after protests last year and stood in recent elections.
Since being charged, Mr Patarkatsishvili had lived in self-imposed exile in Britain and Israel.
A Surrey Police spokeswoman said there was "no indication that the sudden death of Badri Patarkatsishvili was from anything other than natural causes".
She said: "Extensive toxicology testing is yet to be carried out. This will take a number of weeks."
There had been fears that Britain has seen a repeat of the murder of former Russian KGB agent Alexander Litvinenko in November 2006.
Mr Patarkatsishvili spoke recently of his fears for his life after an alleged plot to murder him in London was uncovered, and one reported plan bore similarities to the murder of Mr Litvinenko.
The multi-millionaire businessman was one of Georgia's richest and most controversial men, the BBC's security correspondent Gordon Corera said.
He was deeply involved in the murky world of Georgian politics and had recently spoken of fears of a plot to murder him.
Mr Patarkatsishvili had been a long-time business partner of Russian tycoon Boris Berezovsky, an outspoken Kremlin critic who now lives in exile in London.
The tycoon spent Tuesday in meetings in London, and one person who saw him said there had been "no evidence" the businessman was unwell.
Mr Patarkatsishvili left London at 1900 GMT on that day and returned to his home.
The businessman was with close family members and other unidentified people when he collapsed and died at about 2300 GMT.
An inquest into Mr Patarkatsishvili's death will open on Friday at Woking Coroners Court.