Mexico has expanded a probe into fuel smuggling at seaports highlighted in a 2025 Reuters investigation into cartel-linked fuel crimes, according to a government document reviewed by the news agency.
The February document says the anti-corruption ministry is overseeing internal investigations within the ports of Guaymas, Tampico and Ensenada as well as in the Navy and customs agency. The government previously had acknowledged probes into suspected fuel smuggling at the Port of Tampico and last year arrested 14 people allegedly involved, including customs agents and Navy officials.
Fuel smuggling in Mexico involves falsifying shipping and customs paperwork on fuel coming mainly from the United States. Smugglers evade a steep Mexican tax on imported diesel and gasoline by declaring it to be some other type of petroleum product that’s exempt from the duty. The savings can amount to more than half a cargo’s value.
Illicit fuel and stolen crude are the second-largest source of revenue for Mexico’s cartels behind narcotics, according to the U.S. Treasury Department.
Emboldened smugglers have graduated from truck and rail shipments to using petroleum tankers, a development that U.S. and Mexican security officials say points to collusion between cartels and port insiders.
In its 2025 investigation, Reuters tracked a vessel that offloaded imported diesel in the ports of Ensenada and Guaymas that was declared in Mexico to be tax-free lubricants, costing the government $7 million in lost duties.
The importer was suspected to be a front company for the Jalisco New Generation Cartel, according to three Mexican security officials and an undated government security document viewed by Reuters.