The Department of Defense still has a video tagged secret that purportedly shows an encounter between the U.S. military and a UFO.
According to Vice, the Navy confirmed the development while responding to a Freedom of Information Act request.
The Navy letter to researcher Christian Lambright said it "discovered certain briefing slides that are classified TOP SECRET. A review of these materials indicates that are currently and appropriate Marked and Classified TOP SECRET under Executive Order 13526, and the Original Classification Authority has determined that the release of these materials would cause exceptionally grave damage to the National Security of the United States.
"We have also determined that ONI possesses a video classified SECRET that ONI is not the Original Classification Authority for."
There have been several sightings of UFOs by military pilots, including an infamous 2004 encounter with F/A-18 Super Hornets near the USS Nimitz aircraft carrier off the coast of California.
Video from several sightings, including the Nimitz one, have been released.
Vice followed up with the Pentagon regarding the revelation about the still unreleased video and briefing slides.
"The Department of Defense, specifically the U.S. Navy, has the video. As Navy and my office have stated previously, as the investigation of UAP sightings is ongoing, we will not publicly discuss individual sighting reports/observations," Pentagon spokesperson Susan Gough told the website.
"However, I can tell you that the date of the 2004 USS Nimitz video is Nov. 14, 2004. I can also tell you that the length of the video that's been circulating since 2007 is the same as the length of the source video. We do not expect to release this video."