Germany's domestic intelligence agency chief revealed that North Korea has been acquiring equipment and technology for its nuclear and weapons programmes through its Berlin embassy.
He did not say what parts the North Koreans had allegedly acquired, but he did note that North Korea had skirted restrictions by procuring "dual-use" parts: items that have both civilian and military applications.
He said it was necessary to presume that parts for North Korea's launch program "were acquired via other markets or underground buyers had acquired them in Germany".
"When we detect something of this sort, we take steps to prevent it", Mr Maassen told German television.
Non one at the embassy in Berlin was immediately available for a comment to Reuters.
"We discovered procurement activities taking place there, which we believe were focused on the missile program, and also to some extent on the nuclear program", Maassen said.
As part of the far-ranging sanctions levied against North Korea since the dramatic expansion of their missile and nuclear programs began in early 2017, the United Nations has restricted North Korea from purchasing dual-use parts. "But we cannot guarantee that this can be detected and prevented by us in all cases".
"When we see such things, we stop them".
Last year, North Korea carried out a number of long-range ballistic missile tests. The tests showed that North Korea theoretically can strike anywhere in the USA with a ballistic missile.
The U.N. report found that Pyongyang had continued to export coal, iron, steel and other banned commodities - earning $200 million (€160 million) in revenue previous year.