An old associate of Russian President Vladimir Putin who was demoted after publicly criticising the Kremlin leader has died from an unexplained " serious disease ".
Viktor Cherkesov, once Putin's trusted deputy and the former chief of the Federal Drugs Control Service (FKSN), has died aged 72.
Cherkesov was once in charge of crushing Soviet dissidents and was instrumental to the Russian president’s rise, but the pair later had strained relations.
