The anti-terrorism squad has asked army experts to examine guns and ammunition recovered from an abandoned home in Kozani, northern Greece, on Thursday to verify whether they were stolen from the armed forces.
The materiel was seized after police received a tip-off.
The building belongs to a man who says he is a professor at a university in Leipzig, Germany. He claims to have bought the weapons and the ammunitions at least 15 years ago.
Authorities said they are investigating whether he has any ties to far-right groups.