The accusation clearly sought to parry British suggestions of a serious criminal act on British soil by a man with past links to the Russian security services.
"Litvinenko became an agent who left the control of [British] special services and was killed," Lugovoy, himself a former KGB agent, told a news conference.
"If not by the [British] intelligence services themselves, then under their control or with their connivance."
Lugovoy said Litvinenko and his patron, Boris Berezovsky, a self-exiled Russian billionaire, were both working for British secret services.
"In the words of Sasha [Litvinenko] himself, first he was recruited and afterwards, on his advice, Boris Abramovich [Berezovsky] gave to the British some [Russian] security council documents and also became an MI6 agent," Lugovoy said.
Lugovoy also said British intelligence had tried to recruit him in order to provide compromising information on Vladimir Putin, the Russian president, and his family.
He again dismissed the British charges against him, saying "Britain is making me a scapegoat".
"A real war is being waged against me and Russia in the press," he said.
Lugovoy, who now runs a private security firm in Moscow, has repeatedly denied any involvement in Litvinenko's death.