Among those arrested was a former military attaché who handled classified material for the Bulgarian parliament and a former high-ranking military intelligence officer in the Bulgarian Defense Ministry who, prosecutors claim, was the head of the spy ring.

He and his wife, who has a joint Russian-Bulgarian nationality and was also charged, were allegedly trained by the Russian GRU military intelligence to recruit an “illegal network of agents” made up of people who had access to classified information about Bulgaria, NATO, and the European Union.

“We can conclude that the criminal group has posed a serious threat for the national security by collecting and handing to a foreign country information which constitutes state secrets of Bulgaria, NATO, and the European Union,” said Sitka Mileva, a spokeswoman at the state prosecutor’s office. 

The agent’s wife “played the role of intermediary between her husband and their contact at the [E]mbassy of the Russian Federation,” and passed classified information in return for cash to pay members of their network. 

Prosecutors said that the group had been operating for quite some time and they had been under suspicion. The sweep began when one of the members attempted to flee the country. 

During the Cold War, Bulgaria was one of the Soviet Union’s closest allies, and their intelligence service, the Committee for State Security, conducted operations, including murder, kidnapping, and disinformation against Bulgarian dissidents living abroad. The Committee was accused of the attempted murder of Pope John Paul in 1981. 

But after the collapse of the Soviet Union in 1989, Bulgaria split from the communist playbook and its intelligence apparatus underwent a transformation. Nevertheless, their former Russian allies haven’t stopped trying to exert a presence in the country, even though the Bulgars have joined the EU and NATO. 

The Russian Embassy in Sofia, Bulgaria’s capital, posted a comment on its website saying that “We expect that speculation about Russia’s alleged involvement in intelligence work against Bulgaria’s interests will be halted until there is a court ruling.”

“In the context of the complexity of the international situation, the ‘tireless’ attempts to drive a wedge into the Russian-Bulgarian dialogue and once again demonize our country are obvious,” the Russian Embassy added in its statement. 

The United States State Department said in a statement that it was monitoring the case closely. “The U.S. strongly supports Bulgaria’s sovereignty and stands with Bulgarians against these malign activities on their territory.”

An interesting footnote is that these arrests may affect the upcoming parliamentary elections in Bulgaria on April 4, in which an openly pro-Russian party is running for the first time since the end of the Cold War. Russian intelligence was behind several attempts to influence the 2016 U.S. presidential election, and there may be another attempt to interfere with another country’s internal affairs.

The Bulgarian government has expelled six Russian diplomats in the past two years for alleged espionage activities.