A Russian court has charged a Lithuanian citizen with espionage.
Moscow's Lefortovo court also ruled on May 20 to place the suspect, identified as Arstidas Tamosaitis, into custody for two months.
Russia's Federal Security Service (FSB) earlier said Tamosaitis was detained in Moscow on May 19 while he was "receiving secret documents from a Russian citizen."
The FSB said Tamosaitis admitted being an intelligence officer with the Lithuanian Defense Ministry.
The development comes two weeks after Lithuania announced it had detained a Russian citizen suspected of spying.
The prosecutor's office said the suspect was a Russian FSB security service agent.
It was the fourth criminal case made public by EU and NATO member Lithuania in less than a year involving spying for Russia or Belarus.