Polish authorities have detained an employee of the country’s defense ministry on suspicion of spying for a foreign intelligence agency, the ministry said Tuesday.

The ministry did not name the country involved, but Polish state officials told local media that the suspect had worked with Russian and Belarusian intelligence services.

The 60-year-old detainee, a Polish national, worked in the Ministry of National Defense’s strategy and planning department, including on military modernization projects, officials said. He was arrested at his workplace at the ministry’s headquarters in Warsaw.

The suspect was reportedly a civilian employee rather than a senior official or military officer and had worked at the ministry since the 1990s. He had access to documents considered significant to Poland’s defense, according to the reports.

Following his arrest, counterintelligence officers searched both his office and residence, seizing phones, computers and data storage devices. Prosecutors have charged the man with espionage, though officials said further details would be released only after the investigation is completed.

According to Jacek Dobrzyński, spokesman for the minister-coordinator of special services, investigators collected extensive evidence confirming the detainee’s espionage activities. “The evidence indicates that this man betrayed Poland and acted on behalf of a foreign intelligence service,” Dobrzyński told local media.

Poland has increasingly become a target of what officials describe as Russian hybrid warfare, including sabotage, espionage and disinformation efforts.

In July, Polish authorities said they had detained more than 30 people since the start of Russia’s invasion of Ukraine for allegedly working with Russian intelligence services to carry out acts of sabotage and arson.

In December, hackers believed to be linked to Russia’s military intelligence agency targeted Poland’s power grid, compromising control and communications systems at around 30 distributed energy facilities, officials said.