The Kremlin on Monday (November 20) dismissed allegations that exiled Intelligence agent Alexander Litvinenko, an outspoken critic of Russian President Vladimir Putin, was the victim of an assassination attempt by Russian security services. British police are investigating after Litvinenko, a former colonel in Russia's Federal Security Service (FSB), successor to the KGB, said he fell ill after meeting a contact while probing the murder of Russian journalist Anna Politkovskaya. The hospital said Litvinenko's condition had deteriorated slightly overnight and he had been transferred to intensive care. Doctors say he has only a 50/50 chance of surviving after being poisoned with a highly toxic chemical, thallium. A close friend of Litvinenko on Monday said the former spy was the victim of a plot directed from the heart of the Russian government, but the Kremlin called the statements pure nonsense. Alexei Mukhin, director general of the Moscow-based think tank Political Information Centre, said the Kremlin has no motive to assassinate its former spies. "Putin's position is strong enough and he doesn't need to solve problems in such a way," he said. "There is no political need for that," Mukhin said. Litvinenko, now a British citizen, co-authored a book in 2002 entitled "Blowing up Russia: Terror from Within", in which he alleged FSB agents co-ordinated apartment block bombings in Russia that killed more than 300 people in 1999. The bombings, which authorities blamed on Chechen rebels, led to a shift in public opinion in Russia, affording Putin popular backing for his decision to move troops into Chechnya. In an unrelated development, on Saturday (November 18) Chechen special forces in Moscow shot dead the former head of security for assassinating Chechen President Akhmad Kadyrov. Officials at the scene said Movlaidi Baisarov, who fell out of favour with Kadyrov's son -- Chechen Prime Minister Ramzan Kadyrov -- was killed during a police operation to arrest him for purported involvement in abductions and killings in Chechnya. Russian reports said the Chechen special forces officers were forced to shoot after Baisarov hurled a grenade at the arresting officers. Novaya Gazeta journalist Vyacheslav Izmailov linked Baisarov's murder with that of investigative reporter Anna Politkovskaya, who was shot dead by an unknown assailant in her apartment building on October 7. Izmailov, who worked closely with Politkovskaya on her stories about human rights abuses in Chechnya, believed Kadyrov had ordered both killings. "What happened here in Moscow shows very clearly that the people of Kadyrov can do anything they like on Russian territory," Izmailov said. Kadyrov, 30, became the dominant force after his father President Akhmad Kadyrov, chief Muslim cleric in the separatist leadership who sided with Russia during the second Chechnya war, was killed in a bomb blast in May 2004. He controls hundreds of personal fighters who, with the Kremlin's blessing, impose order on Chechnya's streets alongside a police force that he, as prime minister, also runs. But Human rights groups and ordinary Chechens have accused Kadyrov and his paramilitary security force of kidnapping, torturing and killing civilians.