And counterfeit money is an all-too real problem. Chances are, you could actually have a fake 20 in your pocket right now. One of the best counterfeiters in the world shared his secrets. And ABC's... See More
And counterfeit money is an all-too real problem. Chances are, you could actually have a fake 20 in your pocket right now. One of the best counterfeiters in the world shared his secrets. And ABC's Brian Ross has the story. Reporter: The country is awash in fake money. It is very, very frustrating. It costs us time. It costs us money. Reporter: For the last four years, authorities have been tracking a master counterfeiter, who produced a fake $20 bill that is so good, authorities say it is undetectable by the naked eye. This is really good, isn't it? It's very good. Reporter: This is the man who says he did it. Unabashedly admitting to ABC news, something that could put him in prison for years. His name is frank barassa. I am the world's best counterfeiter right now. It's me. Reporter: He made his fakes in a small town in Canada, outside Montreal. He says it was relatively easy to copy many of the security features of the real 20s. Using the secret service website as a road map. American currency, not that hard to counterfeit? The easiest of them all. Reporter: He found suppliers on the internet, from Europe to China, that could provide the same security features. And used a front company to trick this paper mill in Germany to produce the unique currency paper, made of cotton and linen, complete with Andrew Jackson water marks. Once this is done, the rest is nothing. Reporter: Millions of dollars worth of the fakes went out, he says, before the mountys and the U.S. Secret service moved in. This was going to affect Americans. And it was important to get this right away. Get this off the street. Get it off the market. Reporter: But the counterfeit was so good, he was able to cut the deal of a lifetime for a criminal. In exchange for turning over boxes of the remaining fakes and plates and special paper, he spent only a month and a half in jail. And he says, Canada has agreed not to extradite him to the U.S. I'm safe, absolutely. Can't do nothing about that. Reporter: You beat the system, completely? Yeah, I did. Reporter: And authorities say millions of dollars worth of his fake 20s remain in circulation today, virtually undetectable. Brian Ross, ABC news, Montreal. I'm going to look in my wallet after this. You can see more of Brian's report tomorrow on "20/20." That's 10:00 P.M. Eastern, 9:00 central.
This transcript has been automatically generated and may not be 100% accurate.