Life could not exist on the surface of Mars because the planet has been in a "super-drought" lasting 600 million years, British researchers say.

Scientists at Imperial College London said they based that assertion on analysis of Martian soil from the 2008 NASA Phoenix mission.

Their three-year analysis suggests the Martian surface has been dry for such a long time any possible life would have to be deep underground, The Daily Telegraph reported Friday.

Soil on Mars is formed under arid conditions similar to those on the Moon, the researchers said.

The sample was taken from Mars' icy northern arctic region.

"We found that even though there is an abundance of ice, Mars has been experiencing a super-drought that may well have lasted hundreds of millions of years," research leader Tom Pike said.

"Future NASA and ESA (European Space Agency) missions that are planned for Mars will have to dig deeper to search for evidence of life, which may still be taking refuge underground."