"High treason" carries a sentence of 20 years in prison. Kara-Mursa was arrested in April on charges of spreading misinformation about the Russian military. After the start of the Russian military operation in Ukraine, the parliament in Moscow passed a law that provides for up to 15 years in prison for spreading "false news" about the military.
The former journalist was a confidant of opposition politician Boris Nemtsov, who was murdered near the Kremlin in 2015, and is also close to Russian government critic Mikhail Khodorkovsky.
Kara-Mursa states that he has twice been the victim of poison attacks because of his political commitment. The 41-year-old is one of the few prominent opposition figures still living in Russia.