1.1 billion high-tech hundred-dollar bills have been printed by the U.S. Treasury and Federal Reserve -- and may never see circulation. 

The high-tech hundreds have advanced security features to combat counterfeiters, and were initially scheduled for release in February 2011. But even the printing process for the bills is complex ... so complex in fact that it has led to problems of its own, reported CNBC. 

An unnamed official told CNBC that 1.1 billion of the new bills are unusable because of a creasing problem in which paper folds over during production, revealing a blank unlinked portion of the bill face. A second person familiar with the situation said that at the height of the problem, as many as 30 percent of the bills rolling off the printing press included the flaw, leading to the production shut down.

Officials don’t know exactly what caused the problem, CNBC reported. "There is something drastically wrong here," a person familiar with the situation said. "The frustration level is off the charts."

The new notes retain the traditional look of the U.S. currency, with Benjamin Franklin's portrait, but contain a blue three-dimensional security ribbon with alternating images of bells and the number 100 that change as the viewing angle is tilted. It also has a bell image on the front that changes from copper to green when tilted.

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"As with previous U.S. currency redesigns, this note incorporates the best technology available to ensure we're staying ahead of counterfeiters," U.S. Treasury Secretary Timothy Geithner said in an April statement announcing the bill's release.

The $100 note is the most often counterfeited denomination of U.S. currency outside the United States due to its wide circulation. It is the highest-denominated note issued by the Federal Reserve. In recent years, U.S. officials have struggled to combat the production of extremely high-quality counterfeit $100 notes they say are produced in North Korea, dubbed the "supernote," which are undetectable to nearly all but the most sophisticated currency experts.

When the release of the bills was announced, Federal Reserve Chairman Ben Bernanke stressed that both the current bills and the new ones will both be legal tender.

"It is important to understand when the new design $100 note is issued on February 10, 2011, the approximately 6.5 billion older design $100s already in circulation will remain legal tender," Bernanke had said. "U.S. currency users should know they will not have to trade in their older design $100 notes when the new ones begin circulating."

However, due to the production problems, its doubtful the bills will be released on schedule. A press release issued by the Federal Reserve on Oct. 1 already announced a delay, citing "a problem with sporadic creasing of the paper."

Reuters contributed to this report.