British prosecutors' chief suspect in the killing of ex-KGB agent Alexander Litvinenko claimed Thursday that British intelligence services had a hand in the poisoning - an assertion likely to further damage relations between Moscow and London. Andrei Lugovoi told a news conference he had evidence to back up his claim but would only give details to Russian investigators. Lugovoi, himself a former KGB agent, met with Litvinenko in London hours before he fell ill in November. Britain has requested Lugovoi's extradition to face murder charges. Russia refuses to hand him over. Lugovoi described the British accusations as an attempt to divert attention from Litvinenko's contacts with Britain's spy services. He said Litvinenko had tried to recruit him to work for MI6, Britain's foreign intelligence agency, and gather compromising materials about Russian President Vladimir Putin, but that he had refused. "It's hard to get rid of the thought that Litvinenko was an agent who got out of the secret service's control and was eliminated," Lugovoi said. "Even if it was not done by the secret service itself, it was done under its control or connivance." Britain's Foreign Office declined comment. Oleg Gordievsky, a former top KGB spy who worked for MI6 and defected to Britain, dismissed Lugovoi's claims as "silly fantasies." He said Litvinenko had worked for a domestic intelligence agency in Russia and was of no interest to British intelligence. "Litvinenko was not needed," Gordievsky, who was Litvinenko's friend, said on BBC television. Lugovoi's allegations seem certain to further split Moscow and London over the sensational murder case. Litvinenko died Nov. 23 in a London hospital after ingesting radioactive polonium-210. In a deathbed statement, he accused Putin of being behind his killing. Konstantin Kosachev, the Kremlin-connected head of the foreign affairs committee in Russia's lower parliament house, said on Russia Today television that British authorities should help investigate the "very serious accusations against British secret services." The Russian Prosecutor General's office said it would investigate Lugovoi's statements as part of its own probe into Litvinenko's killing, and was already checking similar claims he made under questioning. Lugovoi claimed British security services were unhappy with Litvinenko for boasting of his contacts with senior MI6 officials and spilling secrets. "In conversations with me, Litvinenko often went beyond his role as a recruitment agent and told me many things he shouldn't have said," Lugovoi said. "I got an impression that he was really getting out of British secret services' control. He believed that the British undervalued him and paid him too little for his service." Lugovoi claimed that Boris Berezovsky, a Russian billionaire and powerful Kremlin political foe living in London, might also have been involved in Litvinenko's death. He said Litvinenko was angry after his longtime friend and patron cut a living allowance he paid Litvinenko. Lugovoi claimed Litvinenko told him he could prove that the tycoon received political asylum in Britain under false pretenses. Russia has long sought Berezovsky's extradition to face charges of financial crimes that he claims are politically motivated. Lugovoi claimed that Berezovsky also was an MI6 agent and gave British intelligence sensitive information about Russia. Berezovsky denied Lugovoi's allegations and said they were part of a Kremlin effort to divert attention from itself. "This is not the story of Lugovoi, this is the story the Kremlin wants to present to the world. The Kremlin is in a corner. Putin is in a corner," he told The Associated Press. Litvinenko fled to Britain in 2000 after he accused the Federal Security Service, or FSB, the main KGB successor, of plotting the kidnapping and killing of Berezovsky and others. He also claimed the FSB was behind fatal apartment bombings in Russia in 1999. Lugovoi and business associate Dmitry Kovtun met with Litvinenko on Nov. 1, the day he said he fell ill. Both men were questioned in the presence of British investigators in Moscow in December. Radiation traces were found at several locations connected with the men, including the hotel bar where they met Litvinenko. They have suggested they were contaminated by Litvinenko during encounters in October.