Tic-tac UFOs and other mysterious "craft" seen swarming US Navy vessels in recent years could be coming from an underwater base, officials have supposedly speculated.

Filmmaker Jeremy Corbell hit headlines around the world when he released the now-famous "pyramid UFO" video, taken by crew aboard the USS Russell off San Diego in July 2019.

He also shared bombshell images of another object appearing above the USS Omaha in the same month before it apparently "descended into the water".

Both sets of material, published on his website extraordinarybeliefs.com, have been confirmed by the Pentagon as genuine.

They follow similar authentic videos of encounters by USS Nimitz fighter jets in 2004 and two more sightings in 2015.

In an exclusive interview with Daily Star, Jeremy claimed there had been discussions between US Navy officials that these UFOs could be coming from Earth's oceans.