Anatoly Maslov, the first of three Russian hypersonic missile scientists from the Siberian city of Novosibirsk to be charged with treason, will go on trial on June 1, the St. Petersburg City Court said.
The 76-year-old Maslov and his colleagues at the Khristianovich Institute of Theoretical and Applied Mechanics (ITAM) -- aerodynamics experts Valery Zvegintsev and Aleksandr Shiplyuk -- are accused of passing classified information to an unspecified country's intelligence agents.
The St. Petersburg City Court also ruled on May 24 that Maslov's detention would be extended until at least November 10. It was said at the hearing that Maslov had been transferred from a detention center in Moscow to a pretrial detention center in St. Petersburg.
The details of the case are classified, but some local media reports cited sources close to scientific circles as saying that the three scholars are suspected of handing information related to their research to China.
Meanwhile, Russian President Vladimir Putin's spokesman, Dmitry Peskov, told reporters on May 24 that the Kremlin does not see any evidence that the scientists might have spied for China.
"I would not draw conclusions about any trends in this case," Peskov said.
Last week, scholars at the Siberian branch of the Russian Academy of Sciences issued an open letter condemning the arrests of the physicists, stressing that the men are innocent and that the ongoing crackdown on scholars in Russia will harm the country's performance in science.
In July 2022, another physicist from Novosibirsk, Dmitry Kolker, died at the age of 54 of cancer while in custody, days after he was arrested as a suspect in a treason case.
Kolker, who held numerous patents and headed the Laboratory of Quantum Optics at Novosibirsk State University, had given lectures at Chinese universities.
Since January 2023, at least 21 treason investigations have been launched in Russia.
Over the last five years, at least 12 employees of the Siberian branch of the Russian Academy of Sciences have been targeted in criminal investigations.