"Consideration of the core appeal has been put off until May 11 because the prosecutor could not come to court," an official in the Moscow City Court said, adding that the prosecutor was in the hospital.
Both the Prosecutor General's Office and lawyers for Grand Duchess Maria have appealed against a November ruling of the Tverskoy Court, which ordered prosecutors to revise Maria Romanov's request to rehabilitate the tsar and his family, killed in 1918, as victims of political repressions rather than murder victims.
Nicholas II, his wife Alexandra, their teenage son Alexei and four daughters were executed together with a doctor and three servants in Yekaterinburg, the Urals, a year after the Bolshevik Revolution of 1917.
The Tverskoy Court also said exoneration of the royal family was a matter for criminal rather than civil proceedings. Prosecutors have said the death of the royal family was "a result of premeditated murder." "We have no legal reasons to recognize Nicholas II and his family as victims of political repressions," a prosecutor said.
But Maria Romanov's lawyer, German Lukyanov, said the executions were not murder but "political repression caused by social and class motivations." "The civil lawsuit presented evidence of the death of the family and documents identifying the reason for the death of Emperor Nicholas II as execution by firing squad," the lawyer said.
The nation's last monarch, Nicholas II and his family were reburied in the former imperial capital St. Petersburg in 1998, 80 years after being massacred by the Bolsheviks.