( AFP ) - Russia has sent Britain an official refusal to extradite the chief suspect in the murder last year of a former Russian agent in London, news agency Interfax quoted sources in Moscow as saying on Thursday.
"According to the country's constitution, it is forbidden to extradite Russian citizens to foreign states," a source said, explaining Moscow's refusal to extradite ex-KGB agent Andrei Lugovoi to face trial for the murder of Alexander Litvinenko.
British prosecutors say Lugovoi poisoned Litvinenko, a former Russian intelligence agent turned Kremlin critic, during a meeting in London in November using a rare radioactive isotope.
Lugovoi maintains his innocence.
The case has severely strained relations between the two countries, in part because Litvinenko had received political asylum and citizenship in Britain.
Russia warned that its constitution forbid extraditions even before Britain had formally made the request, though British Ambassador to Russia Anthony Brenton said Wednesday that Russia had not yet formally responded five weeks after the official request.Lugovoi, now a Moscow businessman, threw fuel on the fire of the extradition struggle with a dramatic press conference in June alleging that the British secret services were involved in the murder of Litvinenko.
He also said British agents had tried to recruit him to find compromising material against President Vladimir Putin.
Last week, Russia's FSB secret service said another Russian national had turned himself over to Russian authorities after Lugovoi's press conference, saying he had spied for Britain and now feared for his life.