Tbilisi/London: Wealthy Georgian businessman Badri Patarkatsishvili, accused of a coup plot against the country's president, has died suddenly in Britain, British police said yesterday.

Officers are treating the death as suspicious and have referred the case to a major crime investigation team. A post-mortem was to be held later yesterday.

Georgian public television said the flamboyant 52-year-old had died of a heart attack at his residence near London.

An ambulance was called to the leafy, secluded mansion late on Tuesday after Patarkatsishvili fell ill while entertaining a large number of friends and family, police said.

Patarkatsishvili's allies in Tbilisi called for international experts to launch an inquiry.

"As far as I know from his relatives, it was his heart," exiled Russian billionaire Boris Berezovsky, a friend and business partner, said by phone from Britain.

In a separate statement, Berezovsky said it was a "terrible tragedy". "I have lost my closest friend," he said. Patarkatsishvili, a prominent figure in his native Georgia, had been living in Britain since last year after Georgian authorities accused him of plotting a coup against the president and issued a warrant for his arrest.

He ran as a candidate in Georgia's presidential election in January, winning 7 percent of votes, but did not campaign in his homeland for fear of detention.

"His death is a big loss for our country. I know he wanted to do a lot of good things for Georgia," former Georgian president and Soviet foreign minister Eduard Shevardnadze said.

Patarkatsishvili held meetings with his public relations team in central London on Tuesday and showed no obvious signs of illness, someone who attended the meeting said.

Rati Shartava, a Tbilisi-based aide to Patarkatsishvili, blamed legal charges brought by President Mikhail Saakashvili's government against the businessman for triggering his death, Russia's Interfax agency reported.

"The state machine fought him and his heart gave in," Shartava said. Georgian government officials declined immediate comment on the businessman's death. Western powers have been eyeing developments in Georgia closely. The country lies on the route of a major oil pipeline in a strategic region bordering Turkey and Russia. It is at the heart of a tussle for influence between former Soviet master Moscow and new allies in the West.

In Moscow, Vladimir Kolesnikov, the deputy head of the security committee of the State Duma (parliament), said that "certain interests could stand behind Badri's death".

Lost empires: Business and politics

- The silver-haired moustachioed Patarkatsishvili, whose name means "son of a little man", was born in Tbilisi on October 31, 1955 and made millions in Russia during the chaotic privatisations of the 1990s.

- He had close links to fugitive Russian tycoon Boris Berezovsky, who wielded huge political influence in Moscow in the 1990s and lives in self-imposed exile in London.

- Patarkatsishvili's Russia-based business interests once included AvtoVaz, the country's biggest car manufacturer, oil company Sibneft and aluminium firm Rusal. After being charged in Russia with fraud, he gave up major stakesin the firms.

- Allies of Saakashvili have said the independent television station Imedi, which Patarkatsishvili co-owned with News Corp, was a mouthpiece for his opponents.

- Saakashvili called elections after the mass protests to demand an early poll. Patarkatsishvili backed the November protests, after which prosecutors accused him of plotting a coup attempt.

- He said on December 27 he was pulling out of his plans to run in Georgia's presidential race.