On June 15, Russian human rights lawyer Ivan Pavlov made public that his client, President of the Arctic Academy of Sciences Valery Mitko, had been under house arrest in St. Petersburg since February, accused of transferring to China classified information on detection of submarines. An internationally recognized expert on underwater acoustics, Mitko, 78, served as captain of 1st rank in the Northern Fleet of the Russian Navy before obtaining a doctoral degree in technical sciences and authoring hundreds of research articles and two textbooks. Public lectures that he delivered in 2017-2018 at the Dalian Maritime University in China have been used against him as evidence of high treason.

On June 22, a Moscow court sentenced Roman Kovalev, the head of the Center for Heat Transfer and Aerodynamics of Russian rocket-building institute TsNIIMash, to seven years in a maximum-security colony for leaking to the West classified materials on hypersonic vehicles. The transfer of information allegedly occurred in 2011-2013 when TsNIIMash collaborated with the Belgian von Karman Institute of Fluid Dynamics on a project approved by Russia. At a hearing that was closed to the public, Kovalev pled guilty to an undisclosed crime in exchange for a sentence below a mandatory 12-year minimum sentence for high treason. According to Pavlov, anyone accused of treason by the FSB (Russian Federal Security Service) has zero chance of acquittal in the Russian court.