Human remains discovered in a forest near the Russian city of Yekaterinburg belonged to the last Russian Tsar Nicholas II and members of his family, the Russian Investigative Committee announced on Friday in a statement.

Since renewing investigations, the Committee has carried out about 37 different forensic examinations.

"Based on numerous expert findings, the investigation has reached the conclusion that the remains belong to Nicholas II, his family and persons from their environment," the Committee said.

Senior investigator Marina Molodtsova told Russian newspaper Izvestia that, "Based on the expert molecular-genetic findings, the remains of the two people, discovered in the summer of 2007 near the burial site of nine other victims, belong to the daughter and son of Nicholas and Alexandra Romanov. Biological kinship with both parents has been established for both Alexei and Maria."

Research is still ongoing, including investigations into how the Russian imperial family was killed.

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Romanov family shrouded in mystery

Nicholas II, his German-born wife Alexandra Feodorovna, and their five children, Anastasia, Maria, Tatiana, Olga and Alexei, were executed by the Bolsheviks in 1918 in the midst of the Russian Revolution.

The Russian Orthodox Church had recognized the ex-tsar as a martyred saint in 1981.

The bodies of the last members of the Romanov dynasty were originally said to have been thrown into a mineshaft, before being burned and hurriedly buried by the killers.

Alexandra Romanova, a spokeswoman for the investigation, told Izvestia that "Our experiments denied the version that the bodies of the victims were destroyed with sulphuric acid and burned."

The remains were first tracked down by amateur historians in 1979, although the discovery was only revealed in 1991 when investigators announced the discovery of the remains of nine people in a burial site in a forest near Yekaterinburg.

They were said to have belonged to the imperial family including Nicholas II, his wife and daughters Anastasia, Tatiana and Olga, as well as their doctor and servants. 

In 2007, researchers conducting an archeological dig south of the original burial, found the remains of what they believed were the two remaining children — Alexei and Maria. The finding led to the reopening of the investigation into the case and the exhumation of the remains of the family.