"The court has announced that it is reversing the lower court's judgement and releasing Radkevich in the courtroom," he said.
Dmitriadis promised to comment on the reasons for the court's decision later, but he said earlier that Radkevich's extradition had been appealed on the grounds that there could have been procedural violations by Interpol and Greek prosecutors.
Radkevich, 53, was detained in Greece last September, but it took some time for the authorities of the two countries to ascertain his identity. He was detained in Greece on a European arrest warrant issued by a Lithuanian court in August.
Several years ago, Vilnius Regional Court sentenced him to four years in prison for driving a tank involved in the events at the Lithuanian capital's Press House.
The Ukrainian appealed against the sentence to the Court of Appeal of Lithuania in December. He had the right to do so even though the verdict had become final, because his case was heard by the court of first instance in absentia.
The Court of Appeal has yet to issue its ruling.
In his letter to the Court of Appeal, the man said he was concerned that his case in Lithuania was political in nature, referring to Lithuanian Foreign Minister Gabrielius Landsbergis' statement that it was "Lithuania's Nuremberg case".
The Ukrainian national is one of 67 people handed prison sentences in the mass trial. The majority of the defendants were convicted in absentia as Russia and Belarus refused to extradite them.
Fourteen civilians were killed and hundreds more were injured when the Soviet troops stormed the TV Tower and the Radio and Television Committee building in Vilnius in the early hours of January 13, 1991.
The Soviet Union used military force in its attempt to remove the legitimate government of Lithuania which declared independence on March 11, 1990.