A US fighter jet pilot rescued by special forces after being shot down over Iran in April described a shocking sight before ejecting from his aircraft: multiple Iranian drones hovering in the air, moving as one, in a formation that resembled a jellyfish, according to four sources familiar with the matter.

The account, which has not been previously reported, was shared by the F-15 pilot with intelligence officials during a debriefing after the incident. It immediately set off a firestorm of debate within the US intelligence community that has yet to be resolved.

US intelligence officials disagreed on how to interpret what the F-15 pilot described, and whether the pilot could recount the incident clearly.

For one thing, he was concussed in the crash. It was his second time being shot out of the sky during the Iran war: he had also been among the pilots downed in a friendly fire incident by Kuwaiti forces early in the conflict, according to two of the sources.

The pilot was rescued hours after ejecting from the aircraft, while the weapons systems officer evaded Iranian capture in the mountains for more than a day before also being rescued. It is not clear if the weapons systems officer also saw the drone formation.