Updated

Mexican marines and police have arrested a man authorities describe as a leading cocaine trafficker for Mexico's Sinaloa drug cartel, authorities said Sunday.

Monte Alejandro Rubido, Mexico's national security commissioner, said Cesar Gastelum Serrano was arrested Saturday in the resort city of Cancun.

Gastelum Serrano was carrying a pistol and 24.7 ounces of cocaine at the time of his arrest, authorities said.

Rubido said that when Gastelum Serrano was in Cancun, "he moved around the area with a low profile, without bodyguards. He did not carry any identification, not even false ones, to avoid detection."

The U.S. Treasury Department placed Gastelum Serrano on its drug kingpin list in December. It called him "one of the most prolific cocaine suppliers for Mexico's Sinaloa Cartel."

The department's Office of Foreign Assets Control said he headed "a vast criminal network to lead a cocaine trafficking organization capable of moving tons of cocaine per week through Honduras and Guatemala to Mexico."

Rubido said Gastelum Serrano operated a family company specializing in scaffolding, which allowed him to move "multiple tons" of cocaine per week. Rubido said he worked with Sinaloa cartel leader Ismael "El Mayo" Zambada -- one of the last of the old-style drug capos still at large in Mexico -- and with Damaso Lopez, who has been mentioned as a possible successor to arrested Sinaloa drug lord Joaquin "El Chapo" Guzman.

Rubido said Gastelum Serrano had operated in Honduras, and had been linked to the killing of law enforcement officials there. He said he operated for a time in San Pedro Sula, Honduras' most violent city, and moved Colombian cocaine through Central America to the U.S. market, as well as distributing drugs in Central America.