No Bilateral Extradition Treaty Between Russia and the UK

The British intelligence forces claim that the Litvinenko poisoning was orchestrated by the FSB, The Times report. This “new” theory comes to light as a team of British investigators is in Russia following the trail of Polonium-210 that killed Litvinenko in London. The British team has probed the British embassy in Moscow where the British authorities interviewed two Russian businessmen regarding potential clues into the casefor any traces of radiation. The Russian authorities are not as cooperative as initially suggested, the CNN reports with a loud headline ("Spy death probe police 'thwarted'") and will not allow the British detectives to question Mikhail Trepashkin, a former FSB officer who has been jailed in 2003 for allegedly divulging state secrets. They will also not be able to question Andrei Lugovoi, a former FSB officer who met with Litvinenko in London, as he has been hospitalized for a second time to be tested for radioactive poisoning. However, as The Observer notes, even if the British authorities were able to establish who is guilty of poisoning the ex-spy Litvinenko, there is no guarantee that the person would ever serve jail time in the UK.
“There is no bilateral extradition treaty between Russia and the UK, and legislation passed by Russia to deal with one-off requests by European countries prohibits the extradition of its citizens. When signing up to the European convention on extradition in 1996, Russia granted itself an exemption in accordance with article 61 of the state's constitution, which says: ‘A Russian citizen cannot be sent beyond the borders of the Russian Federation or given to another state.’"