WELSH scientists have been spearheading the hunt for alien life that may have fallen to Earth in a shower of "red rain".

Astrobiologists will today continue to examine traces of matter that poured its blood-red deluge over the Indian state of Kerala for two whole months in 2001.

Chandra Wickramasinghe, of Cardiff University, is investigating claims made by one Indian researcher that the phenomenon may have been caused by a passing comet depositing extraterrestrial organisms over our planet.

Prof Wickramasinghe, head of the Cardiff Centre for Astrobiology, said, "I think this is potentially extremely important.

"My own personal interest is that for the past 30 years I have worked on the theory that life didn't start on Earth but on comets some 4,000 million years ago and there's an increasing body of evidence to support that point of view.

"We are intercepting cometary material and would expect microorganisms to come to Earth on a semi-regular basis."

The latest research started after red rain fell on the southwestern state of Kerala in August 2001.

Initial speculation suggested the rain's colour was the result of dust swept up by winds across Arabia.

But Godfrey Louis, a physicist at Mahatma Gandhi University in Kottayam, believes the particles that rained down contain types of cell-like organisms markedly different from anything else found on our planet.

Dr Louis said, "The red particles, which were part of the red rain, are possibly of extra-terrestrial origin.

"Under an optical microscope they appear like biological cells and the transmission electron microscopy shows a clear cell structure and their organic nature is indicated by the major presence of carbon and oxygen.

"But despite these biological indications the cells do not show the presence of any DNA.

"The genetic molecule DNA is present in all living organisms found on Earth. So the absence of DNA indicates that they are extraterrestrial."

There were several reports of a sonic boom in the region at the time the rains started, which may be consistent with meteors.