(FILES) A file picture taken 12 July 2007 shows the headquarters (aka Lubianka) of the Federal Security Service (FSB), the former KGB in Moscow. British investigators are accusing former KGB officer Andrei Lugovoi of poisoning ex-spy Alexander Litvinenko with a highly radioactive substance. Russia has turned down a British request to extradite Lugovoi and its own inquiry is ongoing. AFP PHOTO / MAXIM MARMUR (Photo credit should read MAXIM MARMUR/AFP/Getty Images)
