A court in Moscow on December 17 upheld pretrial detention for a Russian physicist specializing in hypersonic aircraft who was arrested earlier this month on suspicion of high treason.
The Moscow City Court rejected Anatoly Gubanov's appeal against a lower court's decision to keep him in custody until at least February 2.
Russian officials have portrayed hypersonic aircraft and missiles as a strategically important military opportunity in the face of mounting tension with the West and Washington's recent decisions to abandon decades-old strategic arms agreements.
In October, the Russian military said it had successfully test-launched a Tsirkon hypersonic cruise missile that flew more than eight times the speed of sound in what President Vladimir Putin hailed as a "big event" for the country.
Gubanov's lawyer, Olga Dinze, said after this week's closed-door hearing that her client was officially charged with high treason and that he had pleaded not guilty.
If convicted, Gubanov could face up to 20 years in prison.
Details of the case, which reportedly revolves around classified materials, have not been made public.
Media reports quoted unnamed sources on December 17 as saying that Gubanov took part in international conferences and projects involving hydrogen-powered hypersonic aircraft, and is suspected of handing classified materials over to foreign secret services.
The scientist is said to be a lecturer at the Moscow Institute of Physics and Technology.
The number of cases of alleged high treason has increased dramatically in Russia during Putin's third and fourth terms as president.
Moscow Court Upholds Scientist's Detention To Await 'High Treason' Trial