United States journalist Evan Gershkovich, accused of spying, goes on trial behind closed doors in the city of Yekaterinburg in Russia.
The 32-year-old is accused of gathering secret information about Uralvagonzavod, a plant manufacturing tanks for Russia’s war in Ukraine, on the orders of the Central Intelligence Agency (CIA).
If Gershkovich gets convicted, he will be sentenced to up to 20 years in prison.
The Wall Street Journal, where Gershkovich worked, as well as the American government have all rejected the claims made by the prosecutors.
Closed trials are standard procedure in Russia for cases of alleged treason or espionage involving classified state material, which typically can last several months.
The Kremlin says the case, and the arrangements for it, are a matter for the court, but has stated, without publishing evidence that Gershkovich was caught "red-handed".
The US has accused Russia of conducting "hostage diplomacy". It has designated Gershkovich and another jailed American, Paul Whelan, as "wrongfully detained" and says it is committed to bringing them home.
The WSJ has declined to comment on the purpose of his reporting trip to Russia's Urals region or on the specific allegation by prosecutors that Gershkovich was trying to gather information on Uralvagonzavod, a supplier of tanks for Russia's war in Ukraine.