An Afghan man claiming to have the decapitated head of Usama bin Laden’s second-in-command has been caught in a lie.

U.S. Defense officials have told Fox News that a man came to a senior U.S. military officer stationed on the ground in Afghanistan and told him he was part of the Al Qaeda security detail surrounding Ayman Al-Zawahiri, bin Laden’s No. 2 man.

The Afghan told the U.S. military that he and another man had murdered Al-Zawahiri, chopping off his head and burying the body. He showed the official a decomposed head that he claimed belonged to the Egyptian terrorist Al-Zawahiri.

The man was seeking the $25 million reward that’s being offered for Al-Zawahiri.

The story traveled through the chain of command and seemed plausible enough to warrant a more in-depth investigation. The severed head was flown from Kabul to the military’s main mortuary in Dover, Del. It was then transferred to a Virginia FBI lab for testing.

Though there are conflicting reports about how it was tested – one source said it was through dental records provided by Egyptian authorities and another said it was through DNA material from Al-Zawahiri’s family – it turned out the head was not that of the wanted terrorist.

The Afghan behind the scam who was after the reward money was told to leave and warned not to try to fool the U.S. military again. It was only this week that U.S. officials were able to confirm the sequence of events.

The incident underscores the interest among Afghan locals for reward money that’s been offered for top Al Qaeda leaders and the lengths the U.S. is going to in order to confirm the identity of remains presented to officials.