UFO enthusiasts are claiming that a proof that alien life has existed in the red planet is once again in one of NASA's official photos.

According to reports, the Mars Curiosity Rover has snapped a photo of an alleged "ancient wall" which was once a part of an ancient city built by an intelligent ancient alien civilization.

The theory was revealed blog post titled "Alien City Ruins on Mars? In Official NASA Images," Daily Star reported.

The blog read:

In the last couple of years, the number of images showing alleged structures on the surface of the red planet has quadrupled. In fact, nearly every single image beamed back by NASA's rovers on Mars seems to show at least one particular ‘object' which appears to be artificially carved or created. While most of these objects are the result of pareidolia, other findings cannot be dismissed so easily.

Back in June, some reports claimed that NASA is covering up an alien city found on Mars after NASA published a photo by NASA's Jet Propulsion Laboratory (JPL) in black and white and in a small "thumbnail" size.

Scott C. Waring of UFO Sightings Daily deliberately accused NASA of hiding evidence that could prove that alien civilizations existed in Mars. According to Waring, NASA published the photo in a smaller size as part of a government policy to hide the structures that could be a breakthrough evidence of extraterrestrial life.

READ: NASA Cover Up? City Found On Mars, Conspiracy Theorists Say

Waring is not the only one who believes so. Dr. John Brandenburg, who has a Ph.D. in Theoretical Plasma Physics from the University of California believes that long ago, a Martian civilization faced hostility and was scraped off of their existence by nuclear bomb-wielding aliens from elsewhere in the universe. His research paper titled "Evidence of a Massive Thermonuclear Explosion on Mars in the Past, the Cydonian Hypothesis and Fermi's Paradox," was published in the Journal of Cosmology.

Meanwhile, agencies geared toward universe exploration have made plans to send mankind to the red planet to discover what is really there. Elon Musk plans to send its first capsule with a human crew to Mars in 2024.