In late July, the remains of a boy and a young woman were exhumed near Yekaterinburg, where Russia's last Tsar, his wife, their four daughters and son, along with several servants, were shot by the Bolsheviks in 1918.
Archaeologists said the site was located after archival documents were recently declassified.
In August, Russian prosecutors reopened a 1993 investigation into the execution of the Romanov family following the alleged discovery of the remains.
Investigator Vladimir Solovyov, who delivered the fragments to the Urals city, told journalists: "I arrived here to compare these remains with the newly discovered remains."
The region's chief forensic expert, Nikolai Nevolin, said at a news conference in August that the remains, believed to be those of the Tsar's son and heir, Alexei, and daughter Maria, including 44 bone fragments, teeth fragments, as well as strips of fabric and bullets, were handed over for examination August 17, and the top prosecutor's office reopened the 1993 case August 21.
"[The bone fragments] will allow for identification of the gender and the relationship of the bodies," Nevolin said.
He said genetic analysis would also reveal whether the boy suffered from hemophilia, a rare hereditary blood disorder that afflicted Crown Prince Alexei. He said the examination could take two months.
Scientists discovered the site after studying written evidence by Yakov Yurovsky, who led the firing squad. He said the prince and one of the princesses had been burned and buried separately from the other nine bodies of the murdered Romanovs and their aides in a bid to cover up the scene.
Parts of the bodies were exhumed in 1991, when the Soviet Union broke up. They were authenticated by experts from Russia, Britain and the U.S. and buried in St. Peter and Paul's Cathedral in St. Petersburg in 1998, and the investigation was dropped.
But in 2004, the results of the forensic examination were challenged, and flaws in the DNA studies, discrepancies between the findings and historical facts and breaches in forensic procedures were reported.
A lawyer representing the Romanovs, German Lukyanov, said in August it was premature to say that the discovered remains belonged to members of the Romanov family.
He also said the decision to resume the investigation was not related to the problem of rehabilitation of the Romanov dynasty, accused by Communist authorities of exerting a bloody tyranny over the nation.
Grand Duchess Maria Vladimirovna Romanov, who lives in Spain, has sought to get the charge cancelled, but a Russian court has rejected her application so far, saying the Tsar's family was not officially sentenced and the execution was ordered by an unauthorized group.
A spokesman for the Romanov family said in August that descendants were prepared to aid the identification process, but warned against rushing to conclusions, which was the case in 1998.
The Romanov family and the Russian Orthodox Church have questioned the authenticity of the remains buried in St. Petersburg.
"If there are sufficient grounds to believe that the discovery is the remains of Crown Prince Alexei and Grand Duchess Maria, if a more detailed examination than that conducted in the 1990s can be carried out, we are certainly prepared to cooperate with the Prosecutor General's Office and any other state and public institution," said Alexander Zakatov.
Russia's Orthodox Church, which has canonized the murdered Romanov family, said it "is looking forward to the results of the genetic analysis," but declined to make any statements until then.
"We would have rejoiced at gaining the remains of the holy royal martyrs," a church official said, adding that the Church would not like to "take part in a political show" similar to the 1998 burial.
