Bulgarian inteligence officer |
The Russian diplomat is the sixth to be expelled on suspicion of espionage from Bulgaria, a NATO member since October 2019.
"The Russian diplomat was declared persona non grata and was given 72 hours to leave," said a foreign ministry spokesman.
The Russian embassy in Sofia said the deportation was unfounded and that Moscow reserved the right to retaliate.
In a statement, prosecutors said the Russian diplomat had attempted to obtain sensitive military information, including the number of US troops stationed in Bulgaria during military exercises.
Prosecutors said they had evidence that the diplomat had been in contact with a Bulgarian citizen who had access to classified information, to whom had been offered money.
Under communism, Bulgaria was Moscow's closest ally in Eastern Europe.