A member who is a suspect and a part of the Mexico's Zetas drugs gang had led authorities to two graves in Veracruz state with 15 bodies.
Marines found the decomposing corpses on two ranches located near the town of Acayucan.
The suspect had given details of the two sites after he had beenarrested when he tried to evade a military checkpoint.
Veracruz has seen an increase in violence during the recent months.
Over hundreds of bodies were found in mass graves during the last few years. Many of them were found in the northern state of Durango and Tamaulipas.
First it was thought that 10 bodies had been found but officials later reported that a total of 15 victims were recovered.