A Russian court on May 21 convicted a 77-year-old physicist of treason and sentenced him to 14 years in a penal colony.
Anatoly Maslov was accused of sharing top secret information on Russia's hypersonic missile program with Germany. He had maintained he was innocent.
The case is the latest in a string of investigations against scientists involved in Russia's hypersonic missile program, responsible for developing such weapons as the Kinzhal and Zircon.
Despite being touted by the Kremlin as "super weapons," they have had limited success against Western-supplied air defense systems in Ukraine, particularly Patriot systems.
Maslov and two of his colleagues at the same institute – Alexander Shiplyuk and Valery Zvegintsev – were arrested in 2022.
Shiplyuk and Zvegintsev are awaiting trial.
The institute previously said the scientific papers the men had presented at international conferences had been vetted to ensure they gave away no secret information but the Kremlin at the time said it was a matter for the security services.
Last year, the Moscow City Court sentenced Anatoly Gubanov, a 66-year-old physicist who worked on hypersonic development, to 12 years imprisonment on treason charges.
Gubanov is the former head of the aircraft and rockets department at the Central Aerodynamics and Hydrodynamics Institute (TsAGI) in Zhukovsky, Moscow Oblast.
He was arrested in 2020 on suspicions that he was providing secret hypersonic development documents to his Dutch colleagues, with whom he collaborated in a civil hypersonic airliner project, HEXAFLY-INT.
Gubanov pleaded guilty, asking judges to take into account all mitigating circumstances and issue a sentence below the minimum threshold of 12 years, which the court rejected.
The physicist's Russian colleague in the project, 70-year-old Valery Golubkin, was detained in 2021 and also sentenced to 12 years imprisonment this year in June. Golubkin rejected the charges raised against him.
Human rights organization Perviy Otdel said that the materials passed by Gubanov and Golubkin to their Dutch colleagues had been examined by three specialized commissions prior to the submission.
The reviews discovered no classified content in the documents, the group said.