A 20-year-old cybersecurity worker has been arrested for allegedly orchestrating Bulgaria’s largest data breach ever. The personal and financial information of millions of Bulgarians were allegedly leaked by a man Bulgarian prime minister Boyko Borissov has called a “wizard” hacker. Bulgaria’s tax agency is now facing fines of $22.43 million for the hack, which is thought to have affected the data of nearly 7 million people. The suspect was arrested and charged with computer crime, which has a maximum sentence of eight years in prison. Police officers raided his home and office, confiscating his computer, which contained encrypted data. Some experts say the data was hacked with relatively basic techniques and that it occurred due to a lack of adequate data protections.

The man has been identified by Bulgarian media as Kristian Boykov. His lawyer said Boykov denies the charges made against him.