The United States admitted on Monday that one of its drones is in Iranian possession.

A senior U.S. military source told Fox News that the Lockheed Martin RQ-170 stealth unmanned aerial vehicle (UAV), which Iran said it downed on Sunday, likely “wandered” into Iranian air space after losing contact with its handlers.

The source said the UAV is presumed to be in tact since it is programmed to fly level and find a place to land, rather than crashing.

“This is a big prize in terms of technology,” the source told Fox News.

While military sources confirmed that the Iranians have the RQ-170 drone, they did not say that the Iranians shot down the spy plane.

After the report in the Iranian media, the U.S.-led coalition in Afghanistan issued a statement saying the aircraft may have been a drone that operators lost contact with last week while it was flying a mission over neighboring western Afghanistan.

A U.S. official said the U.S. had “absolutely no indication” that the drone was shot down.

The RQ-170 Sentinel is made by Lockheed Martin and is equipped with stealth technology, Fox News noted. The $6 million stealth aircraft has an RQ in its name to indicate it is unarmed.

Neither the Air Force nor Lockheed Martin has released much information about the plane.