(CNN) North Korea has been acquiring technology for its nuclear weapons program through its Berlin embassy, according to Germany's intelligence chief.

"We determined that from there (the North Korean embassy in Berlin) weapons procurement took place, in our view, with an eye toward the missile program and in part also the nuclear program," the head of Germany's Security Agency (BfV), Hans-Georg Maassen, told CNN affiliate ARD.

"If we find such things, we stop it, but we cannot guarantee that this can be prevented in all cases," he said in a press release from the public broadcaster ahead of a documentary about North Korea's missile program to be aired Monday.

Maassen said authorities believe parts for North Korea's weapons program were "acquired through shadow buyers or shadow markets abroad, which they then bought in Germany."

Many of the purchases were so-called dual-use goods that could be used for both civil and military purposes, he said.

Read More