LONDON (AP) -- President Vladimir Putin probably approved a plan by Russia's FSB security service to kill former agent Alexander Litvinenko, who died three weeks after drinking tea laced with poison at a London hotel, a British judge said Thursday.
In a lengthy report, Judge Robert Owen said that he is certain Litvinenko was given tea with a fatal dose of polonium-210, a radioactive isotope that is deadly if ingested even in tiny quantities, in November 2006.
He said there is a "strong probability" that the FSB, successor to the Soviet spy agency the KGB, directed the killing, and the operation was "probably approved" by Putin.
Before he died, Litvinenko accused Putin of ordering his killing, but this appears to be the first time anyone has officially linked Putin to it.
Moscow has always strongly denied involvement in Litvinenko's death, and Russian Foreign Ministry spokeswoman Maria Zhakarova said Thursday that the government does not consider Owen's conclusions to be objective or impartial.
"We regret that a purely criminal case has been politicized and has darkened the general atmosphere of bilateral relations," Zhakarova said in a statement. She said Britain's decision to hold a public inquiry on the case was politically motivated and that the process was not transparent for the Russian side or the public.
Russia has refused to extradite the two main suspects, Andrei Lugovoi and Dmitry Kovtun.
Lugovoi is a member of the Russian parliament, which means he is immune from prosecution. In an interview with the Interfax news agency, he called the charges against him "absurd."
"As we expected, there was no sensation," he said. "The results of the investigation that were announced today once again confirm London's anti-Russian position and the blinkered view and unwillingness of the British to establish the true cause of Litvinenko's death."
Litvinenko, a former FSB agent, fled to Britain in 2000 and became a vocal critic of Russia's security service and of Putin, whom he accused of links to organized crime.
Owen said Litvinenko "was regarded as having betrayed the FSB" with his actions, and that "there were powerful motives for organizations and individuals within the Russian state to take action against Mr. Litvinenko, including killing him."
Litvinenko's widow, Marina, said outside the High Court on Thursday that she was "very pleased that the words my husband spoke on his deathbed when he accused Mr. Putin have been proved by an English court."
She called for British Prime Minister David Cameron to take urgent steps against Russian agents operating inside Britain in light of the report.
"I'm calling immediately for expulsion from the UK of all Russian intelligence operatives ... based at the London embassy," she said. "I'm also calling for the imposition of targeted economic sanctions and travel bans against named individuals including Mr (former FSB chief Nikolai) Patrushev and Mr Putin."
She said Britain's Home Office had written to her Wednesday night promising action.
Home Secretary Theresa May is scheduled to discuss the report in Parliament later Thursday.
In his 326-page report, Owen said that based on the evidence he had seen, the operation to kill Litvinenko was "probably" approved by then-FSB head Nikolai Patrushev, now head of Putin's security council, and by Putin.
Owen said Litvinenko "had repeatedly targeted President Putin" with "highly personal" public criticism.
The British government appointed Owen to head a public inquiry into the slaying, which soured relations between London and Moscow. He heard from dozens of witnesses during months of public hearings last year, and also saw secret British intelligence evidence.
Announcing his findings at London's Royal Courts of Justice, Owen said that "there can be no doubt that Alexander Litvinenko was poisoned by Mr. Lugovoi and Mr. Kovtun" in the Pine Bar of London's luxury Millennium Hotel on Nov. 1, 2006. He died three weeks later of acute radiation syndrome.
"I have concluded that there is a strong probability that when Mr. Lugovoi poisoned Mr. Litvinenko, he did so under the direction of the FSB ... I have further concluded that the FSB operation to kill Mr. Litvinenko was probably approved by My. Patrushev, then head of the FSB, and also by President Putin."