Investigators exhumed the mother of one of Mexico's most notorious cartel kingpins Monday, two weeks after thieves apparently made off with her son's body before authorities could conclusively confirm his identity.

Now they plan to do DNA tests to verify that the man they killed in a gunbattle earlier this month was Heriberto Lazcano Lazcano, leader of the Zetas drug cartel, Mexico's attorney general's office said.

Masked federal police Monday guarded the cemetery in central Mexico that houses the mausoleum containing the remains of Lazcano's mother, Mexico's state-run Notimex news agency reported