Lugovoy appeared in Moscow on Tuesday for an interview with Russian media, but was not answering calls to his mobile phone.
The blonde, clean-shaven former agent had previously laughed off reports that he could be extradited to face trial in London, and on Tuesday he dismissed the accusation to state-owned news agency Itar-Tass.
''I consider this decision (by prosecutors) politically motivated,'' Itar-Tass quoted him as saying.
''I did not kill Litvinenko, have nothing to do with his death and can prove with facts my distrust of the so-called evidence collected by Britain's justice system.'' Lugovoy hails from a family whose members served both Tsars and Soviet commissars. He worked in the KGB's prestigious Ninth Directorate guarding the Kremlin elite at the end of the 1980s and the early 1990s.
Details about his life, including his exact age, are scanty, but Russian media have reported Lugovoy left government service in the mid-1990s to run security for Russian state television and later billionaire tycoon Boris Berezovsky.
Ironically Berezovsky, who fled Russia for London after President Vladimir Putin came to power, later became a key benefactor of Litvinenko's and owned the house where the former spy lived.
Russian media have pointed out that Lugovoy's past links to Russian spy services on the one side and to Litvinenko and his key benefactor on the other make him a suspect whose possible motives are hard to fathom.
FOCUS OF INVESTIGATION Lugovoy has been at the heart of the British murder investigation from the outset because he met Litvinenko several times in October and November, including a key meeting at the Millennium Hotel on November 1 along another Russian, Dmitry Kovtun.
Later that day Litvinenko complained of feeling ill and was admitted to hospital shortly afterwards. He died three weeks later, on November 23, from polonium 210 poisoning.
Lugovoy was treated at a Moscow hospital after Litvinenko's death for what some Russian media said was radiation sickness.
British detectives questioned both Lugovoy and Kovtun last year in the hospital as part of their inquiries.
Lugovoy, who refused to answer detailed questions about his movements, always declined to say what he was being treated for.
He has admitted meeting Litvinenko, whom he knew for more than a decade, but said it was part of a normal business relationship.
The former KGB security officer has also lashed out at the British media for its reporting of the case. ''I have been made into some sort of monster in Britain,'' he said.
When asked in January about reports by Britain's Guardian newspaper that his extradition was imminent, Lugovoy replied: ''You can say on Reuters that when Lugovoy was read the Guardian report about my extradition, Lugovoy gave full-hearted, healthy laughter.'' REUTERS NC VC2125