British scientists probing the death of Alexander Litvinenko said on Friday a second man had been poisoned by the same radiation that killed the former Russian spy.
Media reports said the man was Mario Scaramella, an Italian contact whom Litvinenko met at a London sushi restaurant on November 1, the same day he fell ill.
"We are confirming that one further person who was in direct contact with Mr. Litvinenko has been found to have a significant quantity of polonium 210 in their body. This is being investigated further in hospital," a spokesman for the Health Protection Agency said.
"There is likely to be concern for their immediate health."
Police and health authorities declined to confirm the man was Scaramella. Polonium 210 is the same radioactive isotope that poisoned Litvinenko, who died a slow and agonizing death in a London hospital.
The former spy, a British citizen who became an outspoken critic of President Vladimir Putin after leaving Russia's secret service, accused the Kremlin chief of ordering his killing.
Moscow rejects the allegation as ridiculous and has promised to help the British probe, although Foreign Minister Sergei Lavrov said no formal inquiries had yet been received.
The case has triggered a complex police investigation and sparked diplomatic tensions between Britain and Russia.
RADIOACTIVE TRAIL
Britain has also faced a major challenge to reassure the public after traces of radiation were found at 12 sites and aboard planes which have carried more than 33,000 passengers in the past month, many flying between London and Moscow.
Authorities say polonium is not dangerous unless swallowed, inhaled or absorbed through a wound.
Earlier on Friday, three pathologists wearing protective suits to guard against radiation carried out a post-mortem on Litvinenko at the Royal London Hospital.
Scaramella, who describes himself as a security consultant, said last week he had met Litvinenko on November 1 to show him emails from a mutual source warning both their lives may be in danger. He said Litvinenko had told him not to worry.
He has denied poisoning Litvinenko himself.
A lawyer representing Scaramella told Reuters on Friday he was waiting for final test results before making any comments on his state of health.
He declined to explain Scaramella's earlier statements that he was not contaminated, saying the tests were "complex."
EU Commission President Jose Manuel Barroso voiced concern about the case. "We have a problem with Russia. In fact, we have several problems. Too many people have been killed and we don't know who killed them," he said on Thursday.
British media reported on Friday that scientists at the country's Atomic Weapons Establishment had traced the source of the polonium to a nuclear power plant in Russia.
The AWE, the body that provides warheads for Britain's nuclear arsenal, was not immediately available for comment.
The head of Russia's state atomic energy agency Rosatom, Sergei Kiriyenko, told the government daily Rossiiskaya Gazeta Russia produces only 8 grams of polonium 210 a month. He said all goes to U.S. companies through a single authorized supplier.
Kiriyenko said nuclear reactors like the Russian RMBK or the Canadian CANDU were needed to make it.
However Atomic Energy of Canada Limited (AECL), the company that makes CANDU reactors, said Kiriyenko's statement was wrong as the plants could not produce polonium. "It's a totally false statement to suggest that," spokesman Dale Coffin said.