MOSCOW - Russian prosecutors said Thursday they have officially refused Britain's request to extradite a businessman accused in last year's fatal poisoning of former KGB agent Alexander Litvinenko.
Prosecutor General Yuri Chaika's office said its refusal to turn over Andrei Lugovoi was based on a constitutional prohibition against turning over Russian citizens to foreign nations, as well as a European convention on extradition.
In May, Britain accused Lugovoi, a former agent-turned-businessman, of involvement in the killing of Litvinenko, who died in a London hospital in November from a fatal dose of the radioactive substance, polonium-210.
Russian officials including President Vladimir Putin had emphasized that Lugovoi would not be extradited. Putin called the British request "stupidity," saying British authorities should have known about the Russian constitutional prohibition.
In a statement, Chaika's office also said it would consider investigating Lugovoi as a suspect if Britain makes such a request and provides sufficient evidence to justify it. Prosecutors had earlier said they would not rule out prosecuting Lugovoi.
But Russian authorities have tried to turn the tables on Britain by opening their own investigation into allegations of British espionage made by Lugovoi, who also said British secret services and a self-exiled tycoon could have had a hand in Litvinenko's death.
The case has roiled relations between London and Moscow and strained already tense ties between Russia and the West, where governments and rights groups are concerned about the treatment of Putin's opponents.
A spokesman for British Prime Minister Gordon Brown said the British government had not received any formal communication from Russian authorities.
"We await a formal note from the Russians," the spokesman, Michael Ellam, said. "As we've said before, this was a serious crime, and we're seeking and expect full cooperation from the Russian authorities in bringing the perpetrator to face British justice."
Alex Goldfarb, a friend of Alexander Litvinenko and his widow, Marina, called the refusal a "slap in the face."
"It's another (piece of) evidence that the Russian government is behind this murder, because it shows that they have something to hide," Goldfarb said.
He said Litvinenko's widow "expects a reaction from the British government because this was a terrorist attack on a British citizen."
