Brazilian authorities have launched a sweeping operation to dismantle what they describe as the country’s largest tax-evasion and money-laundering network in the fuel sector.

More than 126 search and seizure warrants were executed across five Brazilian states, aiming at multiple individuals and companies allegedly involved in evading over 26 billion reais (approximately $4.8 billion) in taxes.

According to the investigators, the network used a complex web of domestic firms, investment funds and offshore entities — including companies registered in the U.S. state of Delaware — to disguise profits, funnel illicit gains abroad, and subsequently re-introduce them as legitimate investments in Brazil.

Authorities believe the scheme is linked to the notorious organized-crime group First Capital Command (PCC), which has allegedly used dozens of fuel-sector investment funds to launder money.

The government has called for international cooperation, particularly with U.S. authorities, to trace offshore funds, halt illicit financial flows and hold all participants — including individuals hiding behind shell companies — accountable under the law.