Official- Mexican drug boss used police to kill his rival

MEXICO CITY -- U.S. authorities believe Mexico's most violent drug lord, Ramon Arellano Felix, was executed by police working for a rival trafficker and not in a chance run-in with police, a senior U.S. law enforcement official said.

Speaking to reporters Friday on condition of anonymity, the official painted the most complete portrait yet of the downfall of the Arellano Felix brothers, whose Tijuana-based cartel moved tons of cocaine into the United States and is blamed for 300 murders on both sides of the border.

The official's statement conflicted with published reports and accounts by local police in Mazatlan who have said Ramon's death in the Pacific coast resort city on Feb. 10 was the result of a shootout that erupted by chance.

Ramon's death and the March 9 arrest of his brother Benjamin, who was apparently hiding in Puebla, a city east of the capital, dealt a severe blow to Mexico's most feared cartel at a time when it was already struggling under pressure from rivals and big drug seizures by police.

Benjamin was arrested after U.S. agents detected couriers carrying drug money from Tijuana to Mexico City -- not a normal route for the gang's cash. Working on that tip, Mexican federal agents tracked the money and logistics trail from Mexico City to Puebla, where Benjamin surrendered.

Ramon's death and Benjamin's arrest dealt a serious blow to Mexico's most feared cartel at a time when it was already reeling from pressure by rivals and big drug seizures by police, the official said.

The U.S. official said Ismael Zambada, a trafficker based in the Pacific coast state of Sinaloa, may now be poised to take over the Tijuana cartel.