A new variety of very high quality counterfeit US$100 dollar bills or "supernotes" has cropped up in Korea.
KEB Hana Bank said Wednesday that a thorough analysis by a team of specialists at the bank concluded that notes that turned up at a branch at the end of last month were fake.
The bank asked authorities in Korea and the U.S. for a review and was told that these are new supernotes that have never been found anywhere else.
The bills are marked 2006. Series of U.S. currency differ depending on the signatures of the secretary of Treasury Department and director of the U.S. Mint they bear.
Most known counterfeit notes are either from the 2001 or the 2003 series.
The new notes also differ from previous fakes in the way of printing and material, which suggests that a new organization is in charge of printing them, the bank explained.
Lee Ho-jung at KEB Hana Bank said, "It seems that whoever printed these supernotes has the facilities and high level of technology matching that of a government. They are made with special ink that changes color depending on the angle, patterned paper, and Intaglio printing that gives texture to the surface of a note."