New analysis was made after the September reopening of a criminal case into the killing of Nicholas II and his immediate family by the Bolshevik in 1918, the year after he abdicated

New DNA tests comparing the exhumed bones of Russia's tragic last tsar to known royal bloodstains have proved beyond doubt that the final Romanov emperor's remains are genuine, it has been revealed.

And new samples taken from unnamed female descendants of Britain's Queen Victoria genetically match the lower jaw of his controversial German-born empress Alexandra, who brought disgrace on the royals due to her close liaison with crazed monk Rasputin.

The tests were required by the Russian Orthodox Church, which feared that earlier DNA results on bones found buried in mineshafts in the Urals were not sound.

The new analysis came after the September reopening of a criminal case into the killing of Nicholas II and his immediate family by the Bolshevik in 1918, the year after he abdicated.

Fragments of the lower jaw and neck vertebra of the last tsar matched DNA from bloodstained clothing of Alexander II who was assassinated in 1881, said the Russian Investigative Committee, equivalent of the FBI.

The genetic material from the tsar's bones matches a new test on blood from a shirt worn by Nicholas II, then Crown Prince, during an attempt on his life in Japan in 1891.

'In these samples there was found heteroplasmy - a rare genetic mutation which was present in the samples of Nikolai II,' said spokesman Vladimir Markin.

Alexandra's mitochondrial DNA matches 'the blood of the female descendants of the British Queen Victoria', her grandmother, he said.

The bones of the last tsar, his wife, and three of their daughters were dug up in woodland near Ekaterinburg at the end of the Soviet era a quarter of a century ago.

They were buried in St Petersburg in 1998, with tsar-lookalike Prince Michael of Kent representing the Queen, but many churchmen doubted that they were the genuine remains of the Romanovs.

A 2007 find of tiny remains of bones believed to be Crown Prince Alexey and his sister Maria could only be buried once the church is satisfied that all the bones are authentic.

After the royals were gunned down, their remains were cast into old mineshafts by the Bolshevik revolutionaries.

The remains of Nicholas II, the last tsar of Russia, on display in Yekaterinburg

Tsar Nicholas Alexandrovich Romanov (Tsar Nicholas II 1868-1918) and Alix of Hesse (1872-1918), in England at approximately the time of their courtship in the 1890s

Scientists have always maintained that the earlier DNA tests - which involved matches to the Duke of Edinburgh - were genuine.

'The newly-performed tests once again proved the genuine nature of the Ekaterinburg remains,' said Markin.