Geologists at Aberdeen University say tests on meteorites known to have come from the red planet suggest methane may be naturally occurring there.
Experiments showed the gas, which is produced on earth when plants rot and farm animals break wind, can be extracted from Martian volcanic rocks by crushing them.
Previous studies have revealed specialised bacteria living in extreme environments on Earth can use methane to breathe instead of oxygen.
The latest discovery adds weight to the theory that life could potentially survive on Mars, either now or in the past.
Measurements by the Curiosity rover suggest methane levels in the hostile Martian atmosphere are low but the new findings suggest there may greater supplies available below ground.
The significance of the discovery lies in the possibility that methane could be used as a food source by simple life beneath the Martian surface, in the same way as it is on Earth.
The researchers believe chemical reactions between igneous rocks and the environment on Mars could cause them to break down and release enough methane necessary to keep microorganisms alive.
Lead scientist Professor John Parnell, from Aberdeen University’s school of geosciences, said: “One of the most exciting developments in the exploration of Mars has been the suggestion of methane in the Martian atmosphere.
“Recent and forthcoming missions by Nasa and the European Space Agency respectively are looking at this, however it is so far unclear where the methane comes from, and even whether it is really there.
“However, our research provides a strong indication that rocks on Mars contain a large reservoir of methane.
“This is significant because if simple life did exist below the surface then it could use methane as a food source, in much the same way as microbes do in a range of environments on Earth.
“So while we cannot say that this discovery is proof of the existence of life on Mars, it gives strong encouragement to continue looking for methane sources that could support life.”
Co-researcher Dr Sean McMahon added: “Even if Martian methane does not directly feed microbes, it may signal the presence of a warm, wet, chemically reactive environment where life could thrive.”
Prof Parnell said the team’s findings could have major implications in man’s quest to find extraterrestrial life.
“The research has a significance way beyond Mars. Methane is a starting point for complex organic molecules,” he said.
“Our work implies that on many other rocky volcanic planets, in our galaxy and others, there may be methane, which could contribute to the building blocks of life.”
Professor Nigel Blamey, of Brock University in Ontario, said: “The method we use can detect extremely small quantities of gases like methane, and we plan to expand upon our research by analysing more meteorites in the future.”
The study was carried out by at the University of Aberdeen in collaboration with the Scottish Universities Environmental Research Centre, the University of Glasgow and Canada’s Brock University and University of Western Ontario.