A Sydney-based "loyal agent of North Korea" has been charged with trying to sell missile parts and technology on the black market to raise money for Pyongyang in breach of international sanctions, Australian police said on Sunday.

Chan Han Choi, a naturalised Australian citizen of Korean descent, was attempting to broker illicit deals that could have generated "tens of millions of dollars" for North Korea, the Australian Federal Police (AFP) said.

The 59-year-old was involved in discussions to set up a ballistic missile production facility and the supply of missile construction plans in addition to components, software and the transfer of technical expertise from Pyongyang, police alleged.

Neil Gaughan, AFP Assistant Commissioner, told reporters the case was "like nothing we have ever seen on Australian soil", alleging the man was in contact with high-ranking North Korean officials.

"This man is a loyal agent of North Korea, believing he was acting to serve some higher patriotic purpose."