Dogs trained to smell drugs led authorities to the discovery aboard Mexicana Airlines Flight 374, which landed at Benito Juarez International Airport from Caracas, the Venezuelan capital, according to a federal police spokesman.

A statement from the Attorney General's Office said that 585 kilograms of cocaine had been divided into 585 rectangular, plastic packets and stuffed inside the boxes, which had been sealed with tape bearing the airline's logo.

The federal police spokesman said the seizure was 2005's largest and local media said it could turn out to be the biggest in the airport's history.

Earlier this month, Mexico announced a major upswing in the amount of heroin arriving aboard flights from Caracas. The announcement came Nov. 14, at the height of a diplomatic spat between Venezuelan President Hugo Chávez and President Vicente Fox, that prompted both countries to withdraw their ambassadors.

Venezuelan Interior Secretary Jesse Chacón responded last week to the announcement, saying this country should focus more on antidrug efforts in its own territory.