The 54-year-old man is described as a communications specialist who previously served at Greek Air Force headquarters and had access to sensitive NATO information.
According to Greek media, the man confessed during his arrest. He reportedly said he had collaborated with Chinese intelligence after being recruited at a conference abroad, the newspaper Kathimerini reports.
Suspicions were raised when the man took a private trip to China without informing his workplace. At least two other people are being investigated, ERT reports.
