British authorities had tested eight people for possible radiation exposure as the investigation into the death of a former Russian spy continued yesterday.
Meanwhile, speaking from Copenhagen, British Prime Minister Tony Blair talked of his confidence that British police would get to the bottom of Alexander Litvinenko's mysterious death.
Public health officials said a total of 1,121 calls were received to a special hotline in the 48 hours to midnight on Monday.
Of those, 68 were deemed worthy of further investigation, and eight of those were referred as a precaution to determine whether they have been exposed to polonium 210, large quantities of which were found in Litvinenko's urine.
The Health Protection Agency (HPA), which maintains the risk to the wider public "remains low," did not disclose whether Mario Scaramella, an Italian academic who met with Litvinenko on the day he fell ill, was among the eight.
Scaramella was under police guard in London on Tuesday, and was quoted by the Evening Standard as saying: "I am in a house on the edge of London for reasons of protection and security."
"I cannot say where I am because I am being controlled by Scotland Yard. I have always said that I am willing to help them and that is why I am here," he said.
Scaramella, who met former KGB agent Alexander Litvinenko at a central London sushi bar on Nov. 1, also told the newspaper he would retrace his steps to help the investigation.
Litvinenko reportedly feared he had been poisoned by Scaramella according to a friend of his quoted by the Sun tabloid yesterday.
"When I talked to Alexander around 12 Nov. about who poisoned him, we were talking only about the Italian guy Mario," Yuri Felshtinsky, who co-authored Blowing up Russia: Terror From Within with Litvinenko, said.
"He was sure at this time it was Mario. He was telling me that he was in a scheme," he said.
Friends of Litvinenko, however, said before he died that they did not think Scaramella was involved in Litvinenko's death.
Blair, meanwhile, told a news conference in Copenhagen, where he stopped for talks en route to the NATO summit in Latvia, that police would get to the bottom of the affair.
"There is no diplomatic or political barrier in the way of that investigation going where it needs to go," he told a news conference.
"It is obviously a very, very serious matter indeed. We are determined to find out what happened and who is responsible."
The Russian prosecutor-general's office said on Tuesday it was ready to assist the inquiry but had not yet received any formal request, the Interfax news agency reported.
Meanwhile, five locations in London were sealed off after traces of polonium 210 were found.
They include the sushi bar where Scaramella is said to have handed Litvinenko a Russian security services "hit list" with both their names on it and a central London hotel where the former Federal Security Service agent had tea with contacts.
Litvinenko's north London home is also cordoned off, as are the offices of the exiled Russian billionaire Boris Berezovsky and a security company in the plush Mayfair area.
In his first public statement since his death, Berezovsky, who visited Litvinenko in hospital on a number of occasions, said on Tuesday: "I am deeply saddened at the loss of my friend Alexander Litvinenko."