In São Paulo, a consumer's suspicions prompted authorities to investigate a potential fraud, which revealed a billion-dollar scheme of tax evasion and money laundering. The investigation began when a customer reported that a receipt for a purchase of R$ 780 showed a price nearly 30% lower than what they actually paid. This led the police to a company operating at the reported address, which had been engaged in illegal practices for over 20 years.

The company, known as Knup, was founded by Chinese entrepreneurs and sold imported electronic products online. The fraudulent activities were conducted in two main stages: initially, the product's sale price was significantly underreported to reduce tax liabilities; for instance, a product sold for R$ 100 would be declared as costing R$ 30. This dishonest reporting allowed the criminals to evade taxes on their earnings.

Furthermore, the investigation revealed that the amounts involved were distributed across numerous shell companies within the country to further avoid detection by tax authorities. This case highlights the vital role of ordinary citizens' vigilance in identifying and reporting suspicious activities, underscoring its impact on tackling organized crime related to financial fraud in Brazil.