The Guardian reports: The rare radioactive substance used to poison Alexander Litvinenko in London could only have come from Russia, a world-leading expert has told the inquiry into the former spy’s murder.

Norman Dombey, emeritus professor of theoretical physics at the University of Sussex, said the polonium was produced at a closed nuclear facility in the city of Sarov, 450 miles south-east of Moscow. Its Soviet-era Avangard plant was the only place in the world with a polonium “production line”, he said.

“In my opinion, the Russian state, or its agents, was responsible for the poisoning,” Dombey said.

Litvinenko died after drinking a cup of tea laced with radioactive polonium-210, during a meeting in November 2006 at a Mayfair hotel. Two Russians – Andrei Lugovoi and Dmitry Kovtun – have been charged with his murder. The Kremlin has insisted that the polonium involved did not come from Russia. [Continue reading…]