The Italian academic who met the Russian agent Alexander Litvinenko on the day he fell ill was last night being treated in hospital after " significant quantities" of polonium-210 were found in his body.
Mario Scaramella, a KGB specialist who met Mr Litvinenko to warn him of a death threat against both of them, had enough of the lethal radioactive isotope in his body to raise concern for his immediate well-being, although he showed no symptoms of radiation poisoning, doctors said.
Tests have shown that Mr Litvinenko's wife, Marina, has also been exposed to radiation, it was reported last night, although the amounts are thought to have been negligible.
Mr Scaramella was taken to University College London Hospital after tests found polonium-210 in his urine. Last night, the hospital said the quantities were at a "considerably lower level" than those found in Mr Litvinenko, who was treated there before his death nine days ago.
The revelation came as the Kremlin broke its week-long silence to rubbish claims that linked President Vladimir Putin to Mr Litvinenko's poisoning.
Mr Putin's deputy spokesman, Dmitry Peskov, said the Russian president was "disappointed" with British media hysteria that accused him of being behind the poisoning. Without naming them, he speculated that responsibility might be laid at the door of Mr Litvinenko's associates in London, the Russian tycoon Boris Berezovsky and the Chechen militant Akhmad Zakayev, both of whom have been granted asylum in Britain.
He also said Russian authorities had found no trace of radiation at the Moscow airport where BA planes were possibly contaminated. The confirmation that Mr Scaramella ingested the same poison that killed Mr Litvinenko opens up a possibility that the Italian was attacked at the same time as his contact on 1 November.
Detectives have already pinpointed the meeting between the two men at a branch of the Itsu chain in London's Piccadilly or an area in close proximity to the sushi bar as the moment when Mr Litvinenko was poisoned. Mr Scaramella has said that while his companion ate lunch during the 35-minute meeting, he did not, and he drank only water.
The Italian, who has not shown obvious signs of ill health since being exposed, had declared himself to be free of contamination on Thursday, but it is understood this was based on preliminary tests on his clothes.
He arranged to meet Mr Litvinenko, a critic of President Putin, at short notice to discuss documents sent to him by another exiled KGB spy, which outlined a death threat against both men by rogue elements in the KGB's successor, the FSB. The documents, which also named a potential author of the plot to murder the Russian journalist Anna Politkovskaya, said there was a consensus on the "necessity to use force" against both men.
Police sources stressed that Mr Scaramella, who has investigated the smuggling of nuclear material as part of his many areas of activity, was being questioned as a potential witness. He returned to London this week from Rome.
The Italian has been a key figure in the spy novel-style saga. His principal job is an examining magistrate but he also has roles as an environmental campaigner and consultant to the Italian government. He told The Independent that Mr Litvinenko said he was involved in smuggling nuclear material to Switzerland while still serving in the FSB.
The Cabinet Office said the investigation would now retrace all Mr Scaramella's movements. Yesterday, the Ashdown Park Hotel , East Sussex, where Mr Scaramella had been staying since arriving in the UK, was temporarily sealed off as Health Protection Agency officials checked his room for contamination. The managing director of the 106-room hotel, Graeme Bateman, said no other guests had been interviewed but that it reopened after it was declared safe. No one at the hotel had been aware of Mr Scaramella's identity, he said."
In a separate development, Mikhail Trepashkin, a former colleague of Mr Litvinenko, who is serving a four-year prison term for divulging Russian state secrets, said in a letter published yesterday that he had warned him four years ago he was on a list drawn up by an FSB assassination unit set up to eliminate Mr Berezovsky and his supporters.
A post-mortem on Mr Litvinenko was carried out yesterday by three pathologists, each in protective suits. The results will be known in several days.
There was growing consensus in Moscow that the assassination was part of a struggle in the Kremlin between liberals and hardliners who once served in the security services. Julia Latynina, a leading commentator, said the polonium-210 "seems to have been left like a spy's calling card not to prove to the world that Russia is run by the security services, but to prove this to Putin."Reuse content