MEXICO CITY â€"  U.S. officials say the U.S. knew that Mexican marines had killed the head of the widely feared Zetas drug cartel before the body was stolen in a pre-dawn raid from a Mexican funeral home.

One official says the U.S. independently verified the identity of Zeta founder and leader Heriberto Lazcano, killed in a shootout Sunday afternoon in a northern Mexican town, before his body was stolen at gunpoint early Monday.

The account throws into question the Mexican navy's insistence that marines left Lazcano's body unguarded because they thought they had killed a common criminal. They only later discovered from finger prints on the body that it was Lazcano, the navy said.

Both U.S. officials spoke on condition of anonymity because they were not authorized to speak to the press.