According to reports on Saturday, the South Korean military is looking into the disclosure of agents’ personal data who were part of an intelligence unit that was entrusted with spying on North Korea.

According to Yonhap news agency, the Defense Counterintelligence Command launched an inquiry after the Korea Defense Intelligence Command learned around a month ago that secret material, including the personal information of its operatives stationed abroad, had been leaked.

According to reports, undercover agents and official cover agents serving as ambassadors were among the materials disclosed; some spies are believed to have returned home out of fear that their identities would be discovered.

Military authorities have found evidence that the stolen material was intended for the North, and they have also learned that a large number of the operatives impacted by the incident were assigned to missions involving North Korea.

After learning that confidential materials had found their way onto the official’s personal laptop, authorities have opened an investigation into the leak involving a civilian employee of the Korea Defense Intelligence Command.

Though the official has purportedly said that the computer was hacked, authorities assume the laptop to be the source of the leak.

The Korea Defense Intelligence Command has had significant data leaks before. Authorities found in 2018 that a senior officer had been selling classified material abroad since 2013.