MEXICO CITY - Mexico's government thought it had scored the biggest coup of President Felipe Calderón's war on drugs when marines gunned down the founder and leader of the hyper-violent Zetas Cartel in a firefight near the Texas border. But then they lost the body.

Embarrassingly, authorities still haven't found the remains of Heri- berto Lazcano, which were snatched from a funeral home and whisked away by gunmen in a hijacked hearse hours after the Zetas strongman died in a hail of gunfire in the town of Progreso in Coahuila state.

The corpse theft left authorities on Tuesday assuring Mexicans that they got the right man based on fingerprints and photos taken while they still had the body. The navy released two of the photos, showing the puffy, slack face of a corpse whose features, particularly his flaring nostrils, appeared to match the few known photos of Lazcano.

The fallen capo was an army special forces deserter whose brutality and paramilitary tactics transformed a small group of drug cartel enforcers into one of the world's most feared international criminal organizations.

Analysts say his death could set off a power struggle inside the Zetas as its relatively autonomous local cells decide whether to align with its remaining boss, Miguel Angel Trevino Morales, a man considered even more ruthless and brutal than Lazcano.

The killing is also expected to intensify the Zetas' war with the other dominant criminal organization, the Sinaloa Cartel controlled by Mexico's most-wanted man, Joaquin "El Chapo" Guzman.

In the crosshairs of the two cartels' struggle is Nuevo Laredo, a violence-torn city across from Laredo, Texas.

"There will be a shootout at the OK Corral over Nuevo Laredo," predicted George Grayson, an expert on the Zetas.

Calderón, who leaves office in two months, leaving his six-year war as a legacy, stopped short of unreservedly declaring Lazcano dead, but said evidence clearly indicated the Zetas founder had been slain. He said 25 people on a 2009 list of Mexico's 37 most wanted drug lords have been killed or arrested.

The president also praised the marines, the security force responsible for most of the highest-profile take-downs of top level drug bosses in Mexico. Many of those operations were launched in cooperation with U.S. officials, who see the marines as more trustworthy than other Mexican military and law enforcement agencies.

The body's disappearance demonstrated the unchecked control that drug gangs maintain over large swaths of many Mexican states six years into a struggle that shows little sign of abating.

Grabbing the bodies of fallen accomplices is a trademark of the Zetas.

"The Zetas take care of their dead," Grayson said.