Firefighting boats had battled the blaze since Saturday aboard the Burgos, which is owned by the company, Petroleos Mexicanos, or Pemex.
A Pemex statement Sunday night said experts have begun investigating to determine what caused the fire in two of the ship’s tanks. It said specialists from a Texas salvage company had boarded the vessel.
Pemex said a flight over the ship had determined that only a minimal amount of fuel was in the water and it was contained by floating booms.
Earlier in the day, the company had said the Burgos’ double hull had prevented any fuel spill. It said that the volatility of the gasoline and diesel on the ship would aid in its evaporation.
Firefighters used a chemical extinguisher against the fire, the Veracruz Port Authority said.
Mexico’s environmental protection agency, Profepa, said Sunday in a statement that a mile (1½ kilometers) of containment booms were deployed to prevent any spilled fuel from reaching the coast.
The Burgos was carrying about 168,000 barrels of gasoline and diesel, Pemex said.
The ship was anchored about 7 miles off the coast when it called for help at 11:30 a.m. Saturday. All crew members were rescued without injury.
The Burgos had been sailing from Coatzacoalcos in eastern Veracruz state to the Pemex terminal, Port Authority Director Juan Ignacio Fernandez said.