A Paracas skull left compared to an alien grey and an ancient man with elongated skull.

The skulls, found in Peru, created waves in 2014 after a geneticist undertook preliminary DNA tests, and reported unknown results.

He found they had mitochondrial DNA “with mutations unknown in any human, primate, or animal known so far”.

A second round of DNA tests have now been carried out - which some saying the results are just as controversial – leading to further speculation the skull's former owners may not have been from this planet.

Elongated skulls were caused by ancient civilisations purposefully mutilating their skulls from a young age.

It was done by binding the head between two pieces of wood, or binding in cloth.

But, they have always interested alien conspiracy theorists due to the enlarged craniums produced, which appear similar to the mythological alien grey species.

The new tests on the skulls have, however, not aided the alien theory, but have raised new questions about how the Americas were populated.