The FSB said it had charged Russian citizen Robert Shonov, who worked for more than 25 years for the US consulate in the Far Eastern city of Vladivostok, over "cooperation on a confidential basis with a foreign state".
The charge carries a maximum prison sentence of eight years.
Russia on Monday accused a former US consulate employee of illegally passing data about the Ukraine conflict to American diplomats, drawing a protest from Washington, which has called
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