UFO hunters allegedly discovered a pyramid on Mars with a near-perfect structure saying it was built by an ancient civilization, Mirror reported.

The bizarre claim sighting a replica of Egypt's Great Pyramids was backed by the conspiracy theorists through a video footage taken by NASA's Curiosity Rover on May 7, uploaded by YouTube channel, ParanormalCrucible.

The theorists argue that the "near-perfect design and shape" of the "pyramid" seen on an image from NASA is evidence that an ancient civilization once lived on the red planet.

The pyramids are said to be "car-sized" but the alien-hunters say that it may just be the tip of a much larger structure buried beneath.

"None of the Curiosity Rover's subsequent photos taken at 20 to 30 sec intervals in the following few minutes and the subsequent photos hours later, included the object," Exopolitics, a UFO site, reported.

"It appears that the NASA operators of Curiosity deliberately chose not to take another photo or zoom in on the pyramid. If they however did so, none of these subsequent photos were released to the general public."

ParanormalCrucible said that the pyramid in the short video is "the result of intelligent design and certainly not a trick of light and shadow."

Commentators suggest that the pyramids are mere rock formations caused by wind, similar to the ones on Earth.