Thursday marked the 90th anniversary of the slaying of the royal family.
Studies in a number of Russian, Austrian and U.S. laboratories revealed tooth and bone particles dug up last summer are those of two children of Czar Nicholas II, CNN reported Thursday.
The Investigative Committee of the Russian Prosecutor General's Office said the remains of the last emperor's only son, Crown Prince Alexei, 13, and his sister Grand Duchess Maria, aged about 19, were discovered near Yekaterinburg, Russia.
"The remains that were found belong to Alexei and Maria. We can say that with certainty," said Vladimir Solovyov, a senior investigator with the committee.
The czar's family was killed in the cellar of a Yekaterinburg home July 17, 1918, by a faction of the Marxist Russian Social Democratic Labor Party which later made up the Communist Party of the Soviet Union.