Five-thousand-year-old cat bones found in a Chinese farming village have raised new questions about man's complex rapport with domestic felines through history, said a study out Monday.

Cats are widely thought to have been domesticated in ancient Egypt and the Middle East some 4,000 years ago, and the oldest evidence of a wild cat buried with a human on the Mediterranean island of Cyprus dates back even further, to about 10,000 years ago.

So to find evidence of a rapport between cats and humans in between those time periods, and in faraway China, came as a surprise, said lead researcher Fiona Marshall of Washington University.

"First of all, they are in the wrong place in terms of our old ways of thinking," she told AFP.

Working with colleagues at the Chinese Academy of Sciences, the team performed radiocarbon dating and isotope analysis on the bones, found in the village of Quanhucun.

Evidence of carbon and nitrogen in the bones suggest that the cats were feeding on animals -- probably rodents -- that were eating the farmed millet in the area.

Some of the cats appeared to have been eating the millet grains as well, suggesting they either scavenged human food or were fed it.

"It's the first evidence of the food web, the relationship between the food of humans and cats. It's evidence for the process of domestication," said Marshall.

Other findings of the study, published in the Proceedings of the National Academy of Sciences, suggest that the relationship between cats and humans was even closer.

For instance, the bones of an aged cat imply that it was sheltered by an owner and lived longer than it would have been expected to in the wild.

"Even if these cats were not yet domesticated, our evidence confirms that they lived in close proximity to farmers, and that the relationship had mutual benefits," said Marshall.

Until now, domestication of cats was thought to have occurred around 2,000 years ago in China.

The study raises, but does not answer, new questions about how cats came to be in China.

"We do not yet know whether these cats came to China from the Near East, whether they interbred with Chinese wild-cat species, or even whether cats from China played a previously unsuspected role in domestication," Marshall said.

According to Jean-Denis Vigne, a historical cat expert and researcher at France's National Center for Scientific Research, (CNRS) said the study brings new facts to light.

"There was a Chinese history between cats and man," he told AFP. "Until now, this history was limited to the Middle East and Egypt."

He said the study also pointed to the origins of the relationship between cats and humans, which was quite different from dogs and humans.

"Dogs were the pets of hunters and cats were the pets of farmers," he said.

"It's an unusual path toward domestication -- a cat is never totally domesticated," he added.

"Cats maintain a degree of independence from human societies, and they return easily to the wild."