Police evacuated a hotel Friday in southeastern England to test for Polonium-210, the radioactive substance found in the body of ex-Russian spy Alexander Litvinenko, as British health officials confirmed his wife had tested positive for the deadly toxin.

Police in Sussex would only say that they had evacuated a very private hotel located on 186 acres in the countryside, but would not say whether they had found traces of the radioactive substance.

Health officials, meanwhile, told Sky News that clothes worn by Litvinenko's wife, Marina, who had been by his side throughout the ordeal, had tested positive for trace amounts of the poison. The level of contamination was not high enough to warrant concern, officials said.

The mystery of the poisoned spy took an even more bizarre twist Friday when it was revealed that the Italian academic who dined with the ex-KGB agent the day he was poisoned had tested positive for the same radioactive toxin, the British press reported.

Mario Scaramella, who met with Alexander Litvinenko at a sushi restaurant in London, tested positive for isotope Polonium-210, the same radioactive substance that led to the former Russian spy's death, the British Health Protection agency told Sky News.

Doctors at University College Hospital, where Scaramella was being treated, said the level of radiation was not considered dangerous and that he showed no signs of poisoning.

A spokesman said the "there was no danger to the health of people who have been in touch with Scaramella," adding that more tests would be conducted over the weekend.

The Scaramella connection comes on the heels of an Italian press report Thursday that the shadowy nuclear security expert and information peddler was hired to probe possible ties between Prime Minister Romano Prodi and the KGB.

Scaramella reportedly told the former head of a commission that examined cases of past KGB infiltration in Italy that Prodi had carried on "friendly relations" with members of the KGB.

Prodi, who has long denied allegations of cozying up to the KGB, moved yesterday to file a defamation lawsuit relating to the latest inquiry.

Scaramella has said he showed Litvinenko e-mails from a confidential source listing potential targets for assassination, including himself and Litvinenko.

In a letter released Friday by human rights activists, a former Russian security officer -- now jailed -- offered similar allegations, saying he had warned Litvinenko about a government-sponsored death squad that intended to kill him and other Kremlin opponents.

Meanwhile, three pathologists prepared to perform an extraordinary autopsy on Litvinenko at Royal London Hospital's forensic science facility.

Because of the nature of Litvinenko's death by a radioactive toxin, doctors carrying out the examination will take extra safey precautions.

One pathologist will represent the government, another will attend representing Litvinenko's wife, Marina, and the third is an independent specialist in the event the case leads to criminal prosecution.

The 43-year-old former KGB agent's funeral will be held soon after the autopsy, his friend Alex Goldfarb said.

One British newspaper, the Evening Standard, reported that Litvinenko was most probably murdered by "rogue elements" within the Russian state, and that the Polonium-210 that killed him could be traced back to state nuclear laboratories, probably a nuclear power plant.

Meanwhile, Russian Foreign Minister Sergey Lavrov said Moscow was ready to answer any questions about Litvninenko's death.

"When the questions are formulated and sent through the existing channels, we will consider them thoroughly," Lavrov was quoted as saying in Jordan by the ITAR-Tass news agency. "Now the ball is on the English side, and everything depends on the British investigators."

That investigation continued Friday at sites around London and on planes that fly the London-to-Moscow route. A British Airways plane that was grounded in Moscow will be flown back to London to undergo examination on Friday, officials said.

The Health Protection Agency said it has examined 139 people as a precaution, and 24 of those were referred to a specialist clinic.

In a bizarre twist to the story, aides to former Russian Prime Minister Yegor Gaidar, who fell ill in Ireland a day after Litvinenko's death, said Thursday that doctors in Russia believe he, too, was poisoned.

"Doctors don't see a natural reason for the poisoning and they have not been able to detect any natural substance known to them" in Gaidar's body, his spokesman Valery Natarov said. "So obviously we're talking about poisoning (and) it was not natural poisoning."

In a letter from prison released Friday, former Russian security service officer Mikhail Trepashkin said he had warned Litvinenko years ago that the KGB's main successor agency had formed a death squadron to kill him and other Kremlin foes.

Trepashkin said that an officer of the Russian Federal Security Service, known by its Russian acronym FSB, met with him in August 2002 and offered him the chance to join a group targeting Boris Berezovsky, a self-exiled Russian tycoon living in London, and Litvinenko. He said he refused to cooperate with the team, whose task was to "mop up" Berezovsky, Litvinenko and their accomplices.

"Back in 2002, I warned Alexander Litvinenko that they set up a special team to kill him," Trepashkin wrote in a letter dated Nov. 23, which was released Friday by rights activists in Yekaterinburg, the center of the Ural Mountains province where he is serving his four-year sentence. "Maybe, the death of Alexander Litvinenko, who fell victim to unpunished revenge, could force those dealing with human rights issues to finally pay attention to these facts."

An FSB spokesman refused to comment on Trepashkin's claim.

"Alexander Litvinenko's death made me feel angry — angry at the fact that the weak and disorganized human rights movement in Russia could neither prevent political murders nor provide protection to people persecuted by the authorities for political motives," Trepashkin wrote in his letter.

He said he had earlier talked of the FSB's using poisons that could be applied to a car handle, a telephone receiver, an air conditioner or elsewhere to kill a victim without leaving a trace.

Trepashkin was arrested in October 2003 and convicted on charges of divulging state secrets while investigating allegations of FSB involvement in a series of deadly apartment bombings that killed about 300 people in Moscow and two other cities in 1999. The government blamed the explosions on Chechnya-based rebels, but Litvinenko and other Kremlin critics alleged they were staged by authorities as a pretext for launching the current Chechen war.

The FSB, where Trepashkin worked until 1997, alleged that he had been recruited by British agents to collect compromising materials on the explosions with the aim of discrediting the Russian security agency.

A local court released Trepashkin in August 2005 for good behavior after he had served just under half of a four-year sentence, but another court overturned the verdict and put him back in prison about two weeks later.

The Associated Press, Sky News, Times of London and The Independent contributed to this report.