Sverdlovsk Region Governor Eduard Rossel said the tests, conducted by a U.S. laboratory, provided "full confirmation" that the fragments belong to Nicholas II's son and heir Alexis, and his daughter Maria.
The remains were exhumed near Yekaterinburg, where the tsar, his wife, their four daughters and son, together with several servants, were shot by the Bolsheviks in 1918 shortly after the revolution which brought them to power.
The governor's office earlier said the final test results would be made public in late May.
Tests on the bone fragments have been carried out by Russian and foreign scientists.
Initial studies revealed that the remains belong to a boy of about 12-14 years of age and a 16-18-year-old girl. DNA tests conducted in Yekaterinburg and Moscow proved positive.
The tsar and his family members' remains were also discovered near Yekaterinburg in 1991. They were authenticated in a series of tests in Britain, the U.S. and Russia and buried in the St. Peter and Paul Cathedral in St. Petersburg in 1998. Forensic examination results have been challenged since then.
The Russian Orthodox Church, which has canonized the murdered Romanov family, called the 1998 burial "a political show."
