A team of UK scientists are making the latest controversial claim to have found signs of life in a meteorite from Mars. They say their evidence lies in a fragment from a chunk of rock that fell in the Sahara Desert in Morocco in July last year.

The team examined their stone sample under a powerful electron microscope and found tiny egg-shaped globules embedded inside.

The so-called Tissint meteorite, named after a village near where it fell, is known to be from Mars because air trapped inside it has the same recipe as the martian atmosphere. It was probably blasted out of the surface of the Red Planet when it was hit by an asteroid impact several millions of years ago.

A piece of the meteorite was examined by a team of scientists at the Buckingham Centre for Astrobiology and Cardiff University led by Professor Chandra Wickramasinghe and PhD student Jamie Wallis.

Professor Wickramasinghe, 72, is famous for his controversial ideas that viruses including those causing flu epidemics, and even life itself, were brought to Earth by comets. He set up his new centre, which is affiliated to the University of Buckingham, after Cardiff stopped funding his research.

Professor Wickramasinghe says that the globules embedded in the meteorite are rich in carbon and oxygen and that there is no reasonable explanation for them other than that they were produced by living organisms.

He told Skymania that they cannot have been caused by earthly contamination once the meteorite hit the ground. He said: “It is impossible to understand how carbon rich particles of such uniform sizes and shapes got inside a rocky matrix if they are not relics of some algal species.

“Tissant was collected weeks after it fell, and terrestrial contamination seems unlikely. In any case the structures we found were on newly fractured surfaces, from the interior of the meteorite.”

Jamie, whose work is being published in the Journal of Cosmology, itself seen as a rather unorthodox publication, said: “All the indications are that structures such as we have found are evidence of life on Mars. The spheres are probably remnants of polysaccharide shells surrounding algal type cells.”

London’s Natural History Museum has sent fragments of the Tissint meteorite to various British insitutions, but Wickramasinghe’s fragment was apparently secured independently.

Dr Fin Stuart, of the University of Glasgow, is overseeing official analysis of the meteorite. He was unwilling to comment in detail on the Journal of Cosmology paper but told Skymania: “As a general point I would say that the burden of proof for demonstrating life on Mars must be high, and these results do not meet necessary criteria.”

Curator of Meteorites at the NHM Dr Caroline Smith told us she had discussed the new claim with a colleague and said: “Neither of us have any confidence in the structures that they are observing being indicative of any biological entity or process.”

In 2009, a NASA team claimed they had photographed Martian organisms inside another meteorite that is kept in the Natural History Museum. Their electron microscope showed a bumpy surface resembling a fossilised colony of microbacteria in a rock that fell from the sky in Nakhla, Egypt, in 1911, killing a dog.

The team from NASA’s Johnson Space Centre examined the space rock to support their claims in 1996 that Martian bugs had been found in a meteorite, ALH84001, found in Antarctica where it had been lying for thousands of years. That discovery, which NASA later officially backtracked from, was considered so important at the time that President Clinton addressed the nation on TV.

Earlier this month, another group of scientists claimed that the first two Viking probes that NASA landed on Mars in 1976 discovered life but failed to recognise it.