Money is big business in Peru – over the past two years, Peru has overtaken Colombia as the top source of counterfeit U.S. dollars, according to the U.S. Secret Service. In response the service has opened a permanent office in Lima last year (only the fourth such office in Latin America), and has since helped Peru arrest 50 people on counterfeiting charges, CBS News reports.

Over the past decade, $103 million in fake U.S. dollars “made in Peru” have been seized. Unlike most counterfeiters, Peruvians use offset, huge machines that are usually used for printing newspapers, and then they finish each bill by hand to improve the quality.

Most of the fake bills (often $100 bills) are sent to the U.S., but they are also smuggled to nearby Argentina, Venezuela and Ecuador (more $10s and $20s).

Counterfeiters earn up to $20,000 in real currency for every $100,000 in false bills they produce after expenses, investigators report, noting that the business is more profitable than cocaine.