A retired US Navy chief believes the technology that was captured on leaked government footage of a UFO is 100 to 1,000 years ahead of that on Earth.
The leaked video which recorded the skies above San Diego was captured by Navy aircraft and stored in the USS Omaha's Combat Information Centre.
It shows a spherical object flying above the water for a few minutes off the Californian coast before it seemingly vanishes beneath the surface.
Service personnel can be heard saying in the video: 'It splashed", before the object disappears.
America's Defence Department confirmed the clip was recorded by Navy personnel and said the clip is set to be reviewed by the Pentagon's Unidentified Aerial Phenomena Task Force.
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Speaking to CNN Sean Cahil, a retired US Navy Chief Master-at-Arms who served on the USS Princeton said the UFO was concerning.
He said: "First of all the aircraft had zero control surfaces, it had no means of propulsion that we could detect, it moved at hyper-sonic velocities and it preceded the pilots to their cap point, so it seemed to have some knowledge of where the pilots were headed ahead of time.
"We don't possess those abilities to do that in our arsenals at the moment."
Christopher Mellon, former Deputy Assistant Secretary of Defense for Intelligence during the Clinton and George W Bush presidencies, added: "'What we're seeing are a number of distinct and different things.
"Sometimes we're seeing a 50-foot object that can travel at hypersonic speeds and seemingly go into orbit or come down from altitudes of potentially above 100,000 feet."
He added: "They're very capable - in some cases more capable of anything in our own inventory. This has been going on for years. The truth is just emerging."
