The Russian Prosecutor General's office has said that it is reviewing the legality of three Baltic States' independent from the Soviet Union.
A source in the office told state news agency Interfax on Tuesday that the decision on Baltic independence was made by an unconstitutional body. The inquiry initiated after two parliamentary deputies from President Vladimir Putin's party United Russia wrote letters to the Prosecutor General in this regard.
"Legally, the decision to recognize the independence of the Baltic States is defective due to the fact that it was taken by an unconstitutional body," the source said.
The move follows the Russian chief prosecutor's declaration last week that Crimea was illegally handed to Ukraine in 1954, BBC News reported.
Baltic leaders have ridiculed Russia's decision to review the legality of their countries' independence.
"No one has the right to threaten our independence," Lithuania's President Dalia Grybauskaite said, according to Agence France Presse. "Our independence was gained through the blood and sacrifice of the Lithuanian people," she added.
"It's incomprehensible why the Russian Prosecutor General's office would waste its time and resources on this nonsense. The entire issue is legally absurd," Estonia's foreign minister, Keit Pentus-Rosimannus, told EUobserver.
Lithuania's foreign minister also commented on Russia's decision, calling it "a provocation to say at least" and "legally, morally and politically absurd," BBC News reported.
"We think that, employing the logic of these MPs (Russian parliamentary deputies who requested inquiry), we could also question the legal basis of the the governmental independence of the Russian Federation," Ivars Lasis of Latvian Foreign Ministry said, according to Public Broadcasting of Latvia.
The Soviet Union recognized the independence of three Baltic states - Estonia, Latvia and Lithuania - on September 6, 1991. Lithuania was the first of the three Baltic countries to declare independence in 1990, followed by Estonia and Latvia.