A sweeping investigation into fuel trafficking has led to the arrest of 14 people in Mexico, including six members of the Navy — among them a vice admiral — as well as businessmen and former customs officials. Authorities say more arrests are likely.

Attorney General Alejandro Gertz and Security Minister Omar García Harfuch announced the detentions on Sunday, noting that warrants for hundreds more suspects have been requested. Gertz suggested additional government figures could soon face charges.

The investigation began after authorities intercepted the tanker Challenge Procyon in Tampico last March. The vessel carried diesel that should have been subject to a special import tax, but the shipment was falsely declared as a tax-exempt petrochemical.

“This was one of the largest seizures in recent history,” Gertz said, explaining that the bust exposed a broader criminal network.

Fuel theft — known in Mexico as huachicol — has drained Pemex of an estimated US $3.8 billion in the past five years, according to the Associated Press. Each untaxed fuel shipment costs the government around 1 billion pesos (US $51.7 million), Anti-Corruption Minister Raquel Buenrostro said earlier this year.

Security analyst David Saucedo told AP the case underscores deep corruption within government and business circles, noting that such networks “require political, military and police protection.” He added that recent U.S. pressure has driven the tougher crackdown.

Among those arrested was Vice Admiral Roberto Farías Laguna, a relative of former Navy Minister Rafael Ojeda. Gertz emphasized that Ojeda himself is not implicated and had in fact filed a complaint during his tenure that contributed to the investigation.

Also detained was Francisco Javier Antonio Martínez, former Customs director in Matamoros, who later oversaw finances at the port of Tampico. Authorities say his ties to Intanza, a company linked to the Tampico bust, solidified the case against him.

Despite the arrests, García Harfuch stressed that the sailors involved represented “isolated cases” within the Navy and declined to comment on the broader reach of the fuel smuggling networks.