Seng Heng Bank. The U.S. eventually prohibited Americans from banking with Banco Delta Asia. However, an audit of the bank disputed U.S. allegations and indicated that the only time Banco Delta Asia had knowingly handled counterfeit money was in 1994 when it discovered and turned over $10,000 in counterfeit $100 bills to local authorities. The United States has threatened North Korea with sanctions over its alleged involvement with the supernotes, though it said those sanctions would be a separate issue from the nuclear sanctions. South Korea has attempted to play a middle role, encouraging all parties to reach an acceptable conclusion without animosity. In a meeting on January 22, 2006, the U.S. laid out its evidence and tried to persuade the Seoul government to take a harder line on the issue and impose similar financial sanctions, but was rebuffed. South Korea prefers to place blame on North Korean organizations rather than the government, believing that this change in rhetoric can mollify North Korea and be conducive to a resumption of the six-party talks. Several North Korean diplomats have been arrested on suspicion of passing the counterfeit bills, but have used diplomatic immunity to evade charges. On February 2, 2006, banks in Japan voluntarily enforced sanctions on Banco Delta Asia identical to those imposed by the United States. Later in August 2006, the Sankei Shimbun reported that North Korea had opened 23 bank accounts in 10 countries, with the likely intent of laundering more superbills. The U.S. Secret Service estimates that North Korea has produced $45 million in superdollars since 1989. They allege that the bills are produced at the Pyongsong Trademark Printing Factory, which is under the supervision of General O Kuk-ryol. In 2008, a McClatchy Newspapers article reported that the United States no longer explicitly accused the North Korean government of producing supernotes, and that the Swiss Bundeskriminalpolizei, which regularly searches for counterfeit currency, doubted that North Korea produced supernotes. However, in 2009, a report by the Congressional Research Service renewed the accusation. Iran Before the 1979 Iranian Revolution, Iran used intaglio machines to print its currency, as did the United States and other governments. There has been some speculation that Iran has used these to print superdollars. CIA The CIA has been accused of printing and using counterfeit notes to fund off-the-books foreign operations. Klaus Bender, an author of works on counterfeiting, states that the notes are of