Alexander Litvinenko, the poisoned former Russian agent, told the Italian academic he met on the day he fell ill that he had organised the smuggling of nuclear material out of Russia for his security service employers.

Mario Scaramella, who flew into London yesterday to be interviewed by Scotland Yard officers investigating Mr Litvinenko's death, said Mr Litvinenko told him about the operation for the FSB security service, the successor to the KGB.

Police said that Mr Scaramella, who met Mr Litvinenko at a sushi bar in London on 1 November to discuss a death threat aimed at both of them, was a potential witness. He was being interviewed at a "secure location" in London but was not in custody.

In an interview with The Independent shortly after the poisoning became public, Mr Scaramella said that Mr Litvinenko, a friend and professional contact since 2001, told him he had masterminded the smuggling of radioactive material to Zurich in 2000. There have long been concerns that turmoil in Russia and other former Soviet states after the fall of Communism created an international black market in radioactive substances.

The operation would have been one of the last carried out by Mr Litvinenko while still an FSB officer, in a unit tackling organised crime and smuggling. He fled Russia for London that year after the FSB began investigating him for corruption - charges which he claimed were invented as revenge for his decision to expose an FSB plot to assassinate the Russian oligarch Boris Berezovsky.

http://news.independent.co.uk/uk/crime/article2023856.ece

An Italian academic who met former Russian spy Alexander Litvinenko the day he became ill from radiation poisoning is under police protection in London and undergoing medical tests, a legal source said on Tuesday.