US officials have confirmed that one of its stealth drones was on a CIA recon mission

US officials have confirmed that one of its stealth drones, dubbed as the Beast of Kandahar, which was downed by the Iranian Army was on a CIA recon mission.

Two US officials, speaking on condition of anonymity, confirmed that the drone has been part of a CIA reconnaissance mission, involving the United State's intelligence community stationed in Afghanistan, CNN reported on Tuesday.

They said the reconnaissance capability of the RQ-170 Sentinel drone enabled it to gather information from inside Iran by flying along Afghanistan's border with the Islamic Republic.

The unmanned US drone was programmed to automatically return to base even if its data link was lost, one key reason that US officials say the drone likely malfunctioned and was not downed by Iranian electronic warfare.

Iran's official IRNA news agency reported on Sunday that Iran's armed forces had shot down the RQ-170, known as the Sentinel, and is now in possession of it.

US officials rejected that news in the beginning, saying there were no indications the plane was shot down.

The RQ-170 Sentinel, built by Lockheed Martin, was first acknowledged by the US Air Force in December 2009. It has a full-motion video sensor that was used this year by U.S. intelligence to monitor al Qaeda leader Osama bin Laden's compound in Pakistan ahead of the raid that killed him.