MOSCOW: Russia's spy service denied involvement in the poisoning of a former officer of the Federal Security Service (FSB) who is struggling for his life at a London hospital. "We have absolutely nothing to gain from such activities," Foreign Intelligence Service spokesman Sergei Ivanov told the Interfax news agency on Wednesday. The former FSB colonel, Alexander Litvinenko, who fled to Britain in 2001 after being charged with abuse of office, fell ill after meeting a contact in a London restaurant three weeks ago. British doctors said he had been poisoned, but could not immediately identify the poison. They said Mr. Litvinenko's condition was serious. Exiled Russian oligarch Boris Berezovsky, with whom Mr. Litvinenko was closely associated, accused Russian secret services of trying to kill their renegade colleague. Several Russian MPs suggested Mr. Berezovsky may be himself behind the poisoning as it helped him spur a virulent campaign against President Vladimir Putin, whom Mr. Berezovsky regards as his sworn enemy.