MI5 is keeping a closer watch on Russian spies

MI5 has increased its surveillance of suspected Russian spies following the murder of Alexander Litvinenko in London

The director general of MI5, Jonathan Evans, told MPs on the Intelligence and Security Committee his agency was spending more time tracking Russian agents, with Russia accused of Cold War levels of espionage.

"In response to the Litvinenko murder, the Security Service increased its resource dedicated to Russia by around ***," said the ISC's annual report for 2007-08, keeping exact details secret for security reasons.

Mr Litvinenko, a former agent for the FSB, the successor to the KGB, was poisoned by radioactive Polonium-210 in November 2006. The Kremlin has refused to extradite the main suspect, former KGB member Andrei Lugovoy.

The ISC is also to examine the vetting of relatives following the revelation that one of the women in the Max Mosley sex scandal was a partner of a member of the Security Service.

MPs said the intelligence and security services budget was still not enough to counter the terror threat, despite increases.