A court in Moscow has sent a man to pretrial detention on the charge of high treason.
A spokeswoman for the Lefortovo district court said on July 1 that Sergei Petushkov was ordered detained for two months on June 25.
The spokeswoman, Ksenia Pervovlasenko, did not provide any other details, saying that the case materials were classified.
If found guilty, Petushkov faces up to 20 years in prison.
Several Russian citizens have been arrested on charges of high treason or disseminating classified or sensitive information in recent years.