FOR years an army of alien conspiracy theorists have claimed there was an advanced ancient

civilisation once occupying Mars.

Conspiracists claim human-like aliens built temples and structures that mirror those on Earth built by our ancestors.

At its most extreme, the conspiracy theory even suggests life was wiped out on the Red Planet by an inter galactic nuclear war.

However, after keeping out of the debate, Nasa has now spoken to say its years of investigating the Martian surface have found no evidence of anything of sort.

There is agreement between Nasa and the conspiracy theorists that barren Mars was once very different, with great oceans, rivers and lakes covering its surface.

Yet, Nasa rovers that have scoured the surface and beamed back close-up images have found no evidence yet that even the most simplistic forms of single-celled life evolved there.

The theory developed in 1976, when the Nasa Viking space probe sent back an image of the "face on Mars", which many said was an artificially constructed monument, similar to the Egyptian sphinx.