Spy Left Trail of Radiation After Alleged Poisoning

LONDON, Nov. 28, 2006 — -- British investigators are finding more evidence that Alexander Litvinenko left traces of radioactive polonium 210 virtually wherever he went after his alleged poisoning.

Tonight, police are examining two more locations, including the luxury Park Lane Hotel. They have now detected polonium at half a dozen sites: the sushi restaurant where he ate the day he fell ill, the Millennium Hotel where he later met two Russians, his home and the offices of the Russian billionaire and fellow critic of Russian President Vladimir Putin, Boris Berezovsky, where the radioactive material was found Monday night.

Today, Berezovsky confirmed that traces of radiation had been found at his offices in London's West End, explaining that Litvinenko had visited him the day he was allegedly poisoned.

"I am deeply saddened at the loss of my friend Alexander Litvinenko," Berezovsky said in a statement. "I credit him with saving my life and he remained a close friend and ally ever since. I will remember him for his bravery, his determination and his honor."

Police are now trying to determine if members of the public were exposed as well. Today, they announced five more people have been sent for radiological testing after showing symptoms possibly consistent with radiation poisoning. Three others were sent for testing on Monday.

But health officials say the risk is minimal because the traces they're finding are so small. In fact, sources tell ABC News that they've had to bring in special equipment sensitive enough to register the tiniest amount.

So far, more than 1,100 people who visited the contaminated sites have called a special Health Protection Agency hotline.

This reporter was one of them. A camera crew and I entered the now infamous sushi restaurant last Monday to ask permission to film. The manager refused but, unknown to us, we were walking in a contaminated environment.

A health service operator told me we would only have been at risk if we had visited there the day Litvinenko had eaten, Nov. 1, and, in particular, if we'd eaten anything. Reassured, we have not been sent for radiological tests ourselves.

Still, this is clearly an incident that the British authorities are taking very seriously. Some experts have described it as a small-scale terror attack, and the United Kingdom has instituted some of the response steps they would take in the event of a dirty bomb attack.

Four days after Litvinenko's death, there are no real suspects, just theories.

One theory is that the Russian security services, the FSB, killed him either acting on orders from the government or on its own. Litvinenko was a vocal critic of Putin and his government, accusing it of murdering its harshest critics.

Another theory, floated solely in government-controlled Russian newspapers, is that Putin's enemies orchestrated the murder to embarrass him or, more bizarrely, that Litvinenko killed himself.

There are new clues in the weapon, though they might not narrow the field of suspects.

Radioactive polonium 210 is manufactured only in nuclear reactors and is sometimes used in spacecraft. Russia, of course, has both nuclear reactors and a space program.

But polonium can also be found in commercially available photographic anti-static devices. We managed to buy some ourselves.

Prof. Peter Zimmerman, a nuclear physicist at King's College London, told ABC he was amazed at how easy it was to obtain.

"It's a lot easier to get a lethal dose of polonium and to prepare it for administration than we thought," he said. "I think there's a lot of people that could do this."