Story highlights "I would seriously question their ability to do what they say they have done," Panetta says

Tehran bragged about seizing unmanned U.S. drone aircraft in December

Months later, Iranian senior military officials declare they have extracted data from it

The drone's data reveal that it flew over bin Laden's hideout, a military official says

The U.S. secretary of defense said Monday that he doubts Iran has been able to reverse-engineer a U.S. spy drone that crashed last year in the Iranian desert to learn its secrets.

"I would seriously question their ability to do what they say they have done," Leon Panetta told reporters traveling with him to Colombia.

His comments came a day after Iran said it had "cracked the codes" of the intelligence-gathering system in the drone it captured last year for violating its airspace, the nation's semiofficial media reported.

Tehran bragged that it had seized the aircraft in December and displayed it on national television as a victory for Iran.

On Sunday, an Iranian senior military official said the country's military had extracted data from the aircraft in order to prove to the Pentagon that it had been able to decode it.

"This plane is seen as a national capital for us, and our words should not disclose all the information that we have very easily," Brig. Gen. Amir Ali Hajizadeh was quoted as saying by the semiofficial Fars News Agency.

"Yet, I provide four cues in here to let the Americans know how deep we could penetrate into (the intelligence systems and devices of) this drone."

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Data from the drone's memory revealed it had flown over the Pakistani hideout of al Qaeda leader Osama bin Laden two weeks before his death in May, according to Hajizadeh.

"Had we not accessed the plane's softwares and hard discs, we wouldn't have been able to achieve these facts," he said.

Iran has also decoded information including protocols, repairs and flight sorties, said the military leader, who commands the Islamic Revolution Guards Corps' aerospace forces.

The drone was in California in October 2010 for repairs and was moved to Afghanistan the following month, but it had problems that U.S. experts could not solve, he said.

Retired Gen. James "Spider" Marks, a CNN contributor, said the U.S. military should be concerned about this report.

"We have to assume the compromise of the drone is complete," he said Monday on CNN's "Early Start." "They can pick apart different pieces of this drone."

Marks said U.S. officials need to be concerned about how Iran can use this information to counter American technology.

In December, President Barack Obama said the United States had asked Iran to return the drone it said it had. At the time, two U.S. officials said the missing drone was part of a CIA reconnaissance mission that involved both the intelligence community and military personnel stationed in Afghanistan.

"We've asked for it back. We'll see how the Iranians respond," Obama said.

Iranian military officials have vowed not to return the plane.