Russia on Wednesday unexpectedly named Britain's chief suspect in the radioactive poisoning of former Russian agent turned Kremlin critic Alexander Litvinenko as a "victim" in its own probe.
In a surprise twist to the dispute between Moscow and London over the death of Litvinenko in London in 2006 due to polonium poisoning, Russia's Investigative Committee said Andrei Lugovoi and his associate were also poisoned with the substance.
"Andrei Lugovoi has been acknowledged a victim in the criminal case on the murder of Alexander Litvinenko," the Investigative Committee, which probes high-profile crimes, said in a statement.
It said it had opened an investigation on Tuesday into the attempted murder of Lugovoi by "unidentified persons" using the highly radioactive isotope Polonium-210 that killed Litvinenko.
It said it had confirmed "the fact that Andrei Lugovoi was poisoned with Polonium-210 while meeting Alexander Litvinenko in London in October and November 2006."
Investigators said they were now probing as a single case Litvinenko's murder, Lugovoi's attempted murder and the attempted murder of Lugovoi's friend Dmitry Kovtun, who was one of the last to see Litvinenko before he fell ill.
Lugovoi, 45, a former FSB security agent who now represents the nationalist Liberal Democratic Party of Russia in parliament, denies any involvement in Litvinenko's death from radioactive poisoning in London in 2006.
Litvinenko, 43, also a former FSB officer, died in hospital a few days after drinking tea laced with polonium at a London luxury hotel in November 2006. Lugovoi and Kovtun both met Litvinenko at the hotel.
In a deathbed letter, Litvinenko said he believed then-president Vladimir Putin was involved in his killing after he publicly criticised the strongman leader, an ex-KGB agent.
Lugovoi on Wednesday backed the investigators' decision, saying he had always asserted he was a victim of crime.
"I'm satisfied by this decision, since I have been saying for five years that I'm a crime victim both physically and morally," he told the RIA Novosti news agency.
Kovtun also said he agreed with the decision.
"Of course that's how it is. We said this back in 2006," he told the Echo of Moscow radio station.
Litvinenko's widow, Marina Litvinenko, gave an interview to the BBC Russian Service last month saying her late husband, who had become a British citizen, worked as a consultant on organised crime for British secret services.
The announcement on the eve of parliamentary elections defiantly ignores Britain's request to extradite Lugovoi, making clear once again that Russia will not back down on its refusal to accept the British view of the crime.
Moscow's refusal to extradite Lugovoi after the murder sparked tit-for-tat expulsions of diplomats and has long soured its relations with London and
At a September meeting in Moscow, British Prime Minister David Cameron and President Dmitry Medvedev confirmed neither side would budge, but Cameron said the countries should work round the issue in the interests of warmer relations.