A friend of Alexander Litvinenko said he believes the former Russian agent was murdered because he possessed allegedly damaging information about a high-ranking Kremlin figure, the British Broadcasting Corp. reported Saturday.

Yuri Shvets, a former KGB agent now based in the United States, said he and Litvinenko had worked together providing confidential background information for international companies before possible investment in Russia. Shvets told the BBC his friend was poisoned after an eight-page dossier complied by Litvinenko — which allegedly contained sensitive material and has now been given to Scotland Yard — was leaked to the unnamed figure in Moscow.

Shvets said that his friend showed the dossier to Andrei Lugovoi, a former KGB agent and one of the men he met at a London hotel on Nov. 1, the day Litvinenko fell ill.

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Showing Lugovoi the report "triggered the assassination," Shvets said. He told the BBC that he believed Lugovoi was still working for the Russian security services, and had leaked the information to the man in Moscow.

Lugovoi was not immediately available for comment Saturday. In an interview Friday with The Associated Press, he said that when he spoke to detectives from Scotland Yard, it was as a witness, rather than as a suspect.

"Police are not accusing me of anything," he said. "As for all that is being said — it's nothing but hysteria in the media."

Asked if the dossier was the reason for Litvinenko's death, Shvets said yes.

"Well, I can't be 100 percent sure but I am pretty sure," Shvets said. "Obviously there is always room for ... other suspicions but in a tradecraft there is such as thing as most probable cause, most probable theory, and this is the one."

The Metropolitan Police said they would not comment on Shvets' theory.

Litvinenko died Nov. 23 in London after being poisoned with polonium-210, a rare radioactive element. The Kremlin has repeatedly denied any involvement in Litvinenko's death.

Also on Saturday, a British publishing house announced that it intended to publish in English Litvinenko's book, "Blowing Up Russia: Terror from Within," which alleged Russia's the Federal Security Service was behind a string of bombings at Russian apartment buildings in 1999. The bombings killed more than 300 people and were blamed by the Kremlin on Chechen separatists.

Previously, the book had been privately printed, but Gibson Square, the British publishers, said it has never been sold.

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