Biophysicist Tony Taylor said his mongrel had sniffed out bacteria in mud from Queensland state that matched fossils of primitive organisms in a Martian meteorite which plunged into Antarctica 13,000 years ago.
This backed a theory by NASA scientists who examined the potato-sized meteorite, called ALH84001, after it was retrieved in 1984 and concluded 12 years later that life existed on Mars.
Taylor said his 13-year-old Dingo-Kelpie cross named Tamarind had unearthed the mud-bound bacteria while sniffing around in the ooze at Moreton Bay on the Queensland coast in 1990s.
"She's comes along on all my field trips," Taylor told AFP, explaining he had taught the dog to sniff out sediments containing specific bacteria. "It smells like sewage and she knows the word 'stinky'."
Taylor, who works at the Australian Nuclear Science and Technology Organisation in Sydney, said he and colleague Professor John Barry examined 82 different bacteria retrieved from the area identified by the dog and discovered they contained 11 characteristics also found in the Mars fossils, including a structure other scientists claimed could only be formed in intense heat.
"They were a perfect match, absolutely perfect. Eleven features out of 11," said Taylor, whose work, crediting Tamarind, was published Thursday in the "Journal of Microscopy".
"These fossils are four billion years old, they pre-date the fossil record of life here on Earth."
Taylor developed an imaging technique that allowed him to examine the bacteria at a much higher resolution and he is delighted with the findings.
"You have to understand, this has been the most emotional, heated debate in history," he said.
He now believes the combined data warrant a manned mission to Mars to retrieve further samples.
"The results indicate very strongly that life was once there and there are lot of concepts of what we know of life here on Earth that collectively indicate that life might still be there," he said.
"When we say life, we're talking about bacteria, single cell primitive life forms, like we have here on Earth.
"It'd be underground, we'd have to drill down, so these little rovers that are crawling all over the surface would never find it."
Two US-backed rovers are now exploring the red plant and transmitting unprecedented images of the barren landscape.
Taylor said it was likely there were fossils on Mars and they would be well preserved.
"What we've learned from Earth is that as long as there was life on Mars, there probably still is as long there is water in warm rock," he said, adding that data currently being beamed back from the planet indicated there was water on its surface.