UK poisoning probe to go to Moscow

British police investigating the poisoning of Alexander Litvinenko will go to Moscow to speak to witnesses who met the former Russian spy in London shortly before his death, a police source said.

Nine detectives may fly to Moscow as early as today, while others have already visited the United States as part of the probe, the source said, speaking on condition of anonymity.

Interior minister John Reid said the probe into Mr Litvinenko's mysterious poisoning with radioactive polonium 210 was set to broaden. "The police will follow wherever this investigation leads, inside or outside of Britain," he told Sky TV.

From his deathbed, Mr Litvinenko accused Russian President Vladimir Putin of ordering his slow and agonising death, which sparked a health scare in Britain and strained London's relations with Moscow.

The Kremlin denies involvement and has promised full cooperation with the British investigation. Other theories have centred on the possible involvement of rogue Russian agents.

The police source said the dead spy's meeting with Russian citizens at London's Millennium Hotel on November 1 - the day Mr Litvinenko fell ill - was "of interest" but not necessarily the focal point of the police visit to Moscow.

Andrei Lugovoy, a former KGB agent, and businessman Dmitry Kovtun met Mr Litvinenko at the Millennium Hotel. Mr Lugovoy told British newspapers Mr Litvinenko wanted to discuss a business opportunity and he had nothing to do with any attempt on Mr Litvinenko's life.

The Observer reported yesterday that British police officers had gone to Washington to interview a former KGB agent who said he had vital information about the case.

British authorities said last week that traces of radiation had been found at 12 sites and aboard planes that carried 33,000 passengers in the past month. Mr Reid said there was no cause for concern over any health risk.