Vladimir Putin's critics say he's used his power to amass a secret fortune. Reporter Richard Bilton meets former Kremlin insiders who say they know how Putin's riches are hidden.

Vladimir Putin has been accused of corruption on a breathtaking scale. His critics say he's used his power to amass a secret fortune, so is the Russian president really one of the richest people in the world? Reporter Richard Bilton meets former Kremlin insiders who say they know how Putin's riches are hidden.