Robert Shonov, identified as a former employee of the U.S. Embassy in Russia, was arrested in the Russian city of Vladivostok and charged with conspiracy, according to the Russian state news agency Tass.
Vedant Patel, a State Department spokesman, told reporters at a briefing on Monday that he had seen the report but that “I don’t have anything additional to offer at this time.”
Tass, quoting an anonymous law enforcement official, said that Mr. Shonov was accused of “collaboration on a confidential basis with a foreign state or international or foreign organization.” He has been taken to Lefortovo Prison in Moscow, Tass reported, and no court date has been set.
Being held in isolation is commonplace at Lefortovo, a notorious high-security prison whose inmates currently include Evan Gershkovich, the Wall Street Journal correspondent who was accused of espionage in March, charges that his employer and American officials have strongly denied. It is also where Paul Whelan, a former U.S. Marine who is serving a 16-year sentence on what the United States has said are fabricated charges of espionage, was held for 20 months until his trial in 2020. He is now at a forced labor camp several hundred miles away.
In the Soviet era, the K.G.B. kept Soviet dissidents at the prison, and it has been used more recently to isolate opponents of the Kremlin.
