North Korea is found to have continued efforts to counterfeit U.S. dollars while the United States investigated accounts of Banco Delta Asia, a Macau-based bank suspected of money-laundering for the North.

A U.S. State Department report on counterfeiting released Thursday said that Interpol issued an urgent global security alert, known as an Orange Notice, in June after uncovering attempts by Pyongyang to acquire counterfeiting equipment.

The report said that after the U.S. government learned in 1989 that the communist state was forging American dollars, it concluded upon thorough investigation that Pyongyang had been producing and circulating forged one-hundred dollar bills, or so-called “super notes.”