Earlier on Wednesday, the prosecution said in a statement that a pre-trial investigation established that “in the last four years, two Russian citizens have carried out intelligence activities to obtain information about plans to modernize the Bulgarian army.”
"Their goal was to transfer the collected information, including official and state secrets, to Russian military intelligence in Moscow," the prosecution said. It added that the suspects could not be charged with espionage because of their diplomatic immunity.
In January, Bulgaria expelled two Russian diplomats accused of spying, after prosecutors alleged that they had collected information about Bulgaria’s national elections and energy security. Bulgaria, Moscow’s closest ally during the Cold War, is a member of NATO and the European Union but is still struggling to reduce its almost total dependence on Russian energy supplies.