BRITAIN:Former Russian spy Alexander Litvinenko was battling for his life last night after a "dramatic deterioration" in his condition amid deepening mystery as to its cause.
The former KGB colonel - whose friends believe he was the victim of a state-sponsored murder attempt because of his outspoken opposition to President Vladimir Putin and his Moscow regime - was critically ill in intensive care at London's University College Hospital after suffering a heart attack overnight.
The Kremlin and Russia's foreign intelligence service have emphatically denied any involvement, while British police investigating Mr Litvinenko's suspected "deliberate poisoning" reported no significant developments in the case.
At the same time Dr Geoff Bellingan, the director of critical care at UCH, said they thought it unlikely that Mr Litvinenko had been poisoned by thallium. Dr Belling also dismissed suggestions that radioactive material had been used, and said he was concerned by speculation in the media by people not directly involved in Mr Litvinenko's care.
"Despite extensive tests, we are still unclear as to the cause of his condition," said Dr Bellingan, who also said reports that X-rays had identified three objects in his patient's body were "misleading".
Mr Litvinenko's friend Alex Goldfarb said he had been put on a ventilator, was sedated and that the downturn was likely to have reduced his chances of survival.
Chemistry expert Dr Andrea Sella of University College London said the problem facing doctors trying to trace the cause of Mr Litvinenko's illness was that they would not know what they were looking for.
"They have a problem. They have to find some unspecified poison and they do not know what it is. They do not know whether it is a single substance or a mixture. Every day that passes makes their task more difficult."