The Mexican navy says a team of marines had no idea that they had killed the leader of the country's most-feared drug cartel in a gunfight that erupted when they tried to search a group of suspicious men outside a baseball stadium.

Rear Admiral Jose Luis Vergara is the chief navy spokesman and he said in radio and television interviews Wednesday that Heriberto Lazcano's body was left at a funeral home after Sunday's gunfight because marines believed he was just a common criminal and didn't suspect that had just taken down the leader of the Zetas cartel.

Vergara said authorities only realized they had killed a significant figure when armed men stole the body from the funeral home. Fingerprint testing confirmed the dead man was Lazcano.