Britain Seeks Extradition of Ex-KGB Agent

In exile, Litvinenko surrounded himself with other Putin critics. He publicly implicated Russian authorities in a series of apartment bombings in Russia in 1999 that the government blamed on Chechen terrorists.

Litvinenko's family and friends say he dictated a statement on his deathbed accusing Putin of being behind his poisoning.

Alex Goldfarb, who has acted as a family spokesman, said in a telephone interview that "it is obvious" Lugovoy did not secure the rare, exceedingly expensive poison himself. Ninety-seven percent of the legal production of the isotope, one of the world's rarest industrial products, takes place at a closely guarded nuclear reactor in Russia near the Volga River 450 miles southeast of Moscow.

"Clearly it was a state-sponsored job. But who within the Russian state? . . . It must be someone very, very high up," Goldfarb said. "It is unrealistic to think Putin will surrender the perpetrator because he will tell the whole plot to the British."

Adding to the extraordinary details of the case is the involvement of Boris Berezovsky, a Russian billionaire and fierce Putin foe who lives in exile in London. Berezovsky was friendly with both Litvinenko, whom he helped financially when he arrived in London, and Lugovoy, who worked for him when he lived in Russia.

Russian officials have sought the extradition of Berezovsky, accusing him of fraud and other criminal offenses. Britain has refused; Berezovsky has dismissed the charges as a politically motivated campaign against him.

Berezovsky said in a Russian radio interview Tuesday that "bringing charges against Lugovoy effectively means bringing charges against the Russian state, or, to be more precise, against Putin personally, as someone who is at the top of the vertical structure of power."

Russian officials, meanwhile, have insinuated that Berezovsky may have ordered the killing to tar the reputation of Putin.

Margaret Beckett, the British foreign secretary, called the Russian ambassador, Yuri Fedotov, to the Foreign Office on Tuesday and said afterward that "we expect full cooperation from the Russian authorities in bringing the perpetrator to face British justice."

British authorities said they based their extradition case on Russia's signature in 2001 of the 1957 European Convention on Extradition. But experts in extradition law said the treaty allows Russia the option of not extraditing one of its citizens.

Marina Gridneva, a spokeswoman for the Russian prosecutor general's office, said, "Citizens of Russia cannot be turned over to foreign states." She suggested that Lugovoy could be put on trial in Russia with input from British prosecutors.

Litvinenko's widow, Marina, told reporters she was pleased that a suspect had been officially named in her husband's death. "It is important to me that my husband didn't die in vain," she said.

Finn reported from Moscow. Special correspondent Karla Adam in London contributed to this report.