Britain today made an official request to Russia to extradite the man suspected of killing ex-KGB agent Alexander Litvinenko with radioactive polonium-210, deepening a rift between the former Cold War foes.
British prosecutors said last week they wanted to bring Russian businessman Andrei Lugovoy before a British court to try him for the murder of Mr Litvinenko, who died on November 23rd last year after being poisoned with the rare radioactive isotope.
Ambassador Anthony Brenton submitted the request to the foreign ministry in Moscow, a spokesman said.
"I can confirm that today the ambassador submitted to the Russian Foreign Ministry papers requesting the extradition of Mr. Lugovoy," a British embassy spokesman said.
Asked if they had received the documents, an official with the Russian prosecutor general's office said: "We confirm this."
Mr Lugovoy, who has always protested his innocence, met Mr Litvinenko in a London hotel on November 1st, the day Mr Litvinenko fell ill.
The murder of Mr Litvinenko with a highly unstable radioactive isotope in London aroused memories of Cold War espionage and has threatened to derail relations between Britain and Russia, now tied by billions of dollars of trade.
Moscow has refused to hand over Mr Lugovoy to Britain because Article 61 of the Russian constitution forbids the extradition of its citizens.
British officials argue that extradition arrangements exist with Russia since it signed up to the 1957 European Convention on Extradition in 2001.