NASA is speaking out against the assertions from one former employee who claimed alien life was discovered on Mars nearly 50 years ago.

A NASA spokesperson rebutted claims from Gilbert Levin, a NASA employee who helped to spearhead the agency's first trip to Mars in 1976.

'The collective general opinion of the large majority of the scientific community does not believe the results of the Viking experiments alone rise to the level of extraordinary evidence," a NASA spokesman Allard Beutel told Fox.

Gilbert Levin (pictured above) is a former NASA scientists who believes that the agency has already uncovered the first signs of life during a mission to Mars in the 1970s

'Although we have yet to find signs of extraterrestrial life, NASA is exploring the solar system and beyond to help us answer fundamental questions, including whether we are alone in the universe.

From studying water on Mars, probing promising 'oceans worlds,' such as Enceladus and Europa, to looking for biosignatures in the atmospheres of planets outside our solar system, NASA’s science missions are working together with a goal to find unmistakable signs of life beyond Earth.'

In an op-ed published last week in Scientific American titled 'I’m Convinced We Found Evidence of Life on Mars in the 1970s' Levin wrote that a mission to Mars was the first concrete example of biological life on other planets.

'What is the evidence against the possibility of life on Mars? The astonishing fact is that there is none,' writes Levin.

'Furthermore, laboratory studies have shown that some terrestrial microorganisms could survive and grow on Mars.'

Levin pointed to a pair of missions in 1976 when NASA sent its Viking Landers 1 and 2 to Mars - the agency's first-ever trip to the Red Planet.

While there, the landers took several samples from the Martian soil in an attempt to search contents for signs of biological life.

Pictures from NASA's first Mars landing (above) were among the benefits reaped from the Viking missions

One of the tests called the Labeled Release life detection experiment, which was spearheaded by Levin, involved combining martian soil samples with organic compounds and then looking for signs of carbon dioxide.

Any microorganisms that were present in the soil would have metabolized the compound and released CO2, says Levin.

Shockingly, the tests initially turned up a significant four positive results and we duplicated by both landers located 4,000 miles apart on the planet.

Despite the initial success, however, further experimentation from NASA turned up empty-handed when NASA searched for specific microorganisms.

According to the NASA, the tests 'provided no clear evidence for the presence of living microorganisms in soil near the landing sites.'

Nonetheless, Levin says evidence of alien life has been bolstered by other discoveries since the Viking missions like evidence of water and other organic compounds and the failure of 43 subsequent studies on the finding to provide a direct explanation.