Riddle of the Romanovs: Revealed

Investigation into the 1918 execution of Nicholas II of Russia and the rumoured escape of two of his children, a belief fuelled in 1991 when the remains of the royal family were exhumed and the bodies of Crown Prince Alexei and one of his sisters proved to be missing. Scientists scrutinise bone fragments, discovered in a shallow grave close to the first, in the hope of uncovering whether the children survived