The Pentagon has denied reports it was looking for UFOs after details of a top-secret surveillance programme were brought to light.
Officials in Washington confirmed the existence of the Advanced Aviation Threat Identification Programme (AATIP) earlier this month, much to the excitement of UFO enthusiasts across the world.
It was believed to be the first time the US government has admitted to looking for UFOs since 1969.
However, a spokesman for the Department of Defense has backtracked on claims that it was on the hunt for extraterrestrials, blaming 'confusion' for subsequent media reports.
Ufologists allege the agency is simply unwilling to share knowledge about UFOs and the real nature of their work.
Details of the operation were released following an interview with former Department of Defense employee Luis Elizondo published in the New York Times on December 16th.
In the interview, he claimed to have overseen the mysterious AATIP programme, which had been given a $22m (£16.3m) budget through Congress' 'black ops' initiative. It officially ran from 2007 to 2012.
Elizondo claims it is now "beyond reasonable doubt" that Earth has been visited by UFOs.
"There were very distinct observeables. Extreme manoeuvrability, hypersonic velocity without a sonic boom, speeds of 7-8,000mph, no flight surfaces on the objects. A lot of this is backed with radar signal data, gun camera footage from aircraft, multiple witnesses."
Videos which seem to show UFO sightings by US military aircraft were also released, possibly originating from Elizondo himself. The classified footage from 2004 purports to show US Navy jets encountering a small black object in the sky, much to the amazement of pilots who were at the location.
However, the Department of Defense's spy arm, the Defense Intelligence Agency has denied that it has released any documents about the incident. In a statement to The Sun they said:
"There is some confusion about this program and claims about its purpose in press reporting... the Defense Intelligence Agency has not released any information, files or videos."
The Department of Defense insists that the programme's focus was always on foreign-based threats to the United States. "The AATIP's mandate, when it existed, was to assess far-term foreign advanced aerospace threats to the United States", a spokesman said.
UFO expert and former Ministry of Defence employee Nick Pope told IBTimes that programmes such as AATIP are the "perfect hiding places to conduct UFO research" without the hindrance of taxpayer scrutiny.
While some research would have been conducted into foreign-based threats, he says, it is equally likely that AATIP was looking for UFOs.
"The Department of Defense has got themselves into a complete mess about this, considering the pop culture baggage about UFOs and extraterrestrials," he said. The search for UFOs will probably continue albeit under a new programme name, he claims.