The Mexican navy seized 2.4 tons of cocaine stashed in a fishing boat intercepted in Pacific waters.
The navy acted on a tip from U.S. intelligence that drugs might be aboard the Mexican-flagged vessel.
The fishing boat had apparently taken on the cocaine cargo in Colombia; the drug was found hidden in fuel tanks inside sealed compartments.
Five people were arrested in the operation carried out on April 27.
The cocaine cargo was presented by the navy at Salina Cruz, a port in the southern state of Oaxaca.
The Pacific coast abounds in seizures of drugs and money belonging to organized crime, thanks to the trade between Mexican and Colombian cartels.
Confiscated last month in different ports of the country was a total of 2.2 tons of cocaine. The total since December 2006 adds up to 82.4 tons.
Mexican President Felipe Calderon has declared open war against the cartels and since he took office has established a strategy of attacking organized crime.
Some analysts have noted the role played by the navy in these seizures, having been responsible for intercepting great quantities of narcotics, with scarcely any armed clashes, unlike the army and federal police, which have 65,000 troops deployed nationwide.
The navy was also the force that took down powerful drug lord Arturo Beltran Leyva last December.