Jaime Maussan, journalist and UFO researcher displayed 1,000 years old fossilised bodies of alleged alien beings before politicians attending a special session at Mexico's parliament.
The fossilised bodies were retrieved from Cusco in Peru.
"These specimens are not part of the evolution of our world. They were not recovered from a UFO scrap. They were found fossilised in a diatom moss mine," Maussan said, testifying under oath.
The Mexican Congress session comes weeks after another appearance before the US Congress, but this one's material was considerably more astonishing.
The National Autonomous University of Mexico (UNAM) studied the samples, according to Maussen, and the researchers who were able to obtain DNA samples used radiocarbon dating to establish their age.
The fossils were discovered to be coated with sand despite the thorough investigation.
"We are not alone in the vast universe, we need to accept this reality," said Maussan, who argued that the public has the right to learn about non-human beings and technologies.
Ryan Graves, a former US pilot, and Avi Loeb, a professor of astrophysics at Harvard University, were in attendance with Maussen. In addition, Graves provided testimony during a July congressional hearing.
Although it is now widely acknowledged in both scientific and political circles that there are extraordinary phenomena that cannot be explained, there are still significant differences of opinion over how they came to be.
Maussen testified under oath, however, his assertions have not been supported by evidence, and he has been linked to disputed discoveries.