Annual Treasury Report on Counterfeiting of U.S. Currency Abroad

The full report is here, but it’s a big, fat, nasty pdf. Here’s the section on North Korea:

6.5.7 North Korea and the Supernote Since 1989, the U.S. Secret Service has led a counterfeit investigation involving the trafficking and production of highly deceptive counterfeit notes known as supernotes. The supernote investigation has been an ongoing strategic case with national security implications for the U.S. Secret Service since the note’s first detection in 1989. The U.S. Secret Service has determined through investigative and forensic analysis that these highly deceptive counterfeit notes are linked to the Democratic People’s Republic of Korea (DPRK) and are produced and distributed with the full consent and control of the North Korean government.

In March 2005 and again in June 2006, Interpol issued an “Orange Alert” regarding the DPRK and its continued quest to obtain or purchase printing supplies that would facilitate the counterfeiting of U.S. currency. The U.S. Secret Service is working very closely with the intelligence community in analyzing supernote distribution activity and monitoring the broader illicit affairs of the DPRK. Over the course of this sixteen-year investigation, approximately $22 million in supernotes has been passed to the public (table 6.5), and approximately $50 million in supernotes has been seized by the U.S. Secret Service.

Emphasis mine.