Marina Litvinenko, widow of Russian former spy Alexander Litvinenko, speaks during an interview in central London on Jan. 23, 2015. Her former secret agent husband died in 2006 of radiation poisoning, and Britain alleges that Russia was involved.JUSTIN TALLIS/AFP / Getty Images
A long-awaited inquiry into the death of Russian former spy Alexander Litvinenko opened Tuesday with the revelation that the KGB agent turned Kremlin critic may have been poisoned with radioactive polonium not once – as authorities initially thought – but twice.
The disclosure by lawyer Robin Tam is the latest twist in a saga that includes allegations of state-sponsored assassination and murky events that Tam said "would not disgrace the pages of a thriller."
Tam, the inquiry's legal counsel, said evidence suggested that Litvinenko had ingested the highly radioactive isotope polonium-210 in mid-October, 2006, and then again about two weeks later.
Litvinenko, who had become a Britain-based critic of the Kremlin, became violently ill on Nov. 1 after drinking tea with two Russian men at a London hotel. He died three weeks later of "acute radiation syndrome."
Britain has accused Russia of involvement. Moscow denies the claim, and has refused to extradite the two men identified by Britain as the prime suspects.
Litvinenko's extraordinary killing – and his deathbed statement that he was poisoned on orders from President Vladimir Putin – soured Russian-British relations for years. Judge Robert Owen, who is overseeing the inquiry, said "the issues to which his death gives rise are of the utmost gravity."
Tam said that after Litvinenko became sick, a trail of radiation was discovered across London that could have put "many thousands of members of the public" at risk.
He said detectives found "a large number of positive traces" of polonium in places visited by Litvinenko and the two suspects: Dmitry Kovtun and former KGB agent Andrei Lugovoi.
Tam said the inquiry would hear evidence that Litvinenko "was poisoned with polonium not once, but twice" and the poisoning "met with at least some success" on both occasions. Litvinenko complained of feeling ill a couple of weeks before he was hospitalized.
The inquiry would also hear from a witness who says Kovtun asked him if he knew a London cook who could put a "very expensive poison" in Litvinenko's food, Tam said.
Kovtun and Lugovoi have strongly denied any involvement with Litvinenko's death. The judge said they have been invited to give evidence to the inquiry by video link from Russia.
Litvinenko's widow, Marina, has said she hopes the inquiry will reveal the long-buried truth about her husband's death.
The investigation first stalled because Russia refused to hand over the suspects, then because British authorities would not disclose secret intelligence evidence. Under the terms of the inquiry, that evidence will be heard, but in secret.
Public hearings are due to last until April, and Owen said he hoped to publish his findings by the end of the year.
Tam said the inquiry would look at Litvinenko's role in Russia's first Chechen war and his later sympathy for the Chechen cause, and would hear evidence that the ex-spy converted to Islam on his deathbed.
Tam said the inquiry would try to cut through the swirl of conjecture and conspiracy theories, including claims that Litvinenko had been killed because of his work with Britain's MI6 intelligence agency, Spanish authorities or private security consulting.
He said evidence would look at Litvinenko's relationships with the late Russian oligarch Boris Berezovsky and with slain journalist Anna Politkovskaya, and his increasingly vocal criticism of the Kremlin.
Tam said the judge would need to consider whether such actions would have made Moscow authorities regard him "as an irritant, or worse."
Owen has said that he has seen secret British government material that "established a prima facie case that the Russian state was responsible" for Litvinenko's death.