Nick Pope, who investigated the strange phenomena for the Ministry of Defence, compared the believers to the X-Files series character Fox Mulder.
The famous fictional FBI agent, portrayed by David Duchovny, investigated alleged paranormal mysteries alongside his sceptical colleague doctor Dana Scully, played by Gillian Anderson.
The US government has acknowledged a top-secret project at the Pentagon – called the Advanced Aerospace Threat Identification Program (AATIP) – ran for four years officially from 2008.
Top officials working alongside scientists from Bigelow Aerospace examined videos of UFOs, and reportedly studied debris from crashed spaceships.
Top officials working alongside scientists from Bigelow Aerospace examined videos of UFOs, and reportedly studied debris from crashed spaceships, while working out whether craft used extraterrestrial technology to travel at such extreme speeds.
Mr Pope stars in a new documentary called Aliens at the Pentagon, director by Michael Long, which lifts the lid on the Pentagon secret programme.
And Mr Pope claims it is not long before a full disclosure could reveal everything the US government knows about UFOs.
He said: “I identify what I think can best be described as a ‘believer faction’ within the US government, a maverick group of scientists and defence officials who genuinely think UFOs might be alien, and who are interested in a wide range of other paranormal phenomena.
“These real-life Fox Mulders were thrilled when the Pentagon got money to look at all this, but the government needed to distance itself from these topics, so a lot of the work was contracted out to Robert Bigelow’s company, Bigelow Aerospace.
“One reason the government wanted to distance itself from this was because interest in UFOs and the paranormal went against the religious beliefs of some senior Pentagon officials, who regarded such things as demonic.
“Aliens at the Pentagon is aimed at reigniting interest in the story of the Pentagon’s UFO project at a critical moment in history.
“The US Congress is demanding to know how the millions of dollars pumped into UFO research were spent and what taxpayers got for their money.
More than 40,000 Americans have taken out insurance against being abducted by aliens.
“Washington is abuzz with rumours that formal Congressional hearings are imminent, and we may be closer than ever to getting an answer to the question of what the US government knows about UFOs.”
Daily Star Online reported recently a key White House committee could be planning a groundbreaking public hearing on the Pentagon project.
The influential US Armed Services Committee has been investigating the money spent on the top-secret X-Files project.
It emerged that former Nevada Democrat Harry Reid, who pushed for AATIPs creation in 2007, suggested the US military could harvest technology from UFOs to be more powerful than enemies.
Reid wrote “the technological insight and capability gained will provide the US with a distinct advantage over any foreign threats and allow the US to maintain its preeminence as a world leader”.