An employee of the Military History Department and a teacher at the Academy of Military Arts were detained in Poland.
The man kept about 3,000 personal files of intelligence officers and materials containing child pornography.
Military police detained the teacher on Tuesday, Gazeta.pl reports.
He is currently under the supervision of the prosecutor of the military department of the Warsaw District Prosecutor's Office.
In addition to the Military Police, the Military Counterintelligence Service is also involved in this matter.
Experts found out that the man had repeatedly visited the Belarusian city of Vitebsk as part of his work at the Military History Bureau.
During searches of the teacher's home, about three thousand personal files of special services personnel were found.
If the man is found guilty, he faces up to 10 years in prison.
