"There is very good reason to believe that animals are the reservoir and ultimately the source of how it gets introduced into the (human) population," WHO team leader Robert Breiman said at joint press briefing here Friday.

After a week-long probe in SARS-hit Guangzhou city the WHO found the coronavirus which causes the sometimes fatal pulmonary disease in cages housing civet cats at a restaurant where one of China's two current suspected cases worked.

"In the restaurant where the first suspected (SARS) case worked the cages that held the civet cats were swabbed and subjected to sophisticated testing," Breiman said, referring to a 20-year-old waitress who has been in quarantine at a hospital for about three weeks.

"Those tests did reveal on each of the cages the presence of SARS coronavirus. Not in one cage actually but on essentially all of them the coronavirus was detected."

Up to now, the WHO considered a direct link between civet cats and patients uncertain, even though some of the earliest SARS victims from the outbreak that eventually killed nearly 800 worldwide last year were wildlife dealers.

"That doesn't necessarily prove anything, but it certainly fits in with the concept that at some point civet cats there were carrying the SARS coronavirus," Breiman said.

Although the WHO is still awaiting final test results from its laboratories, the possibility that the waitress will become a confirmed SARS case is high, said Tang Xiaoping, director of the People's No 8 Hospital.

Tang added that a lower count of SARS antibodies found in the other suspected case -- a 35-year-old businessman -- substantially lessened his chance of becoming a confirmed case.

Earlier this month, scientists from mainland China and Hong Kong said the virus found in civet cats at wildlife markets was almost identical to the coronavirus found in a Chinese man confirmed to have SARS.

The man, a 32-year-old journalist who was China's first confirmed case in six months, reported having no contact with civets or other animals, except for a mouse. He has already been released from hospital.

Because civet cats are popular and expensive cuisine in this part of the country, the findings led to a government order to slaughter all civet cats being bred or sold in Guangdong. The culling ended a week ago.

Wang Zhiqiong, deputy director of Guangdong's health department, said 3,903 civet cats had been slaughtered.

The coronavirus was also identified at one of the animal markets selling civet cats in Guangzhou, Breiman said.

Although many vendors in the markets swear they have never gotten sick despite being in contact for years with the animals, a study by universities in Shenzhen and Hong Kong suggests otherwise.

Not only does the study show that 70 percent of civet cats were SARS coronavirus carriers, but some 40 percent of wildlife dealers had antibodies for the disease.

"We still don't know exactly what role the civet cats play in the process of transmitting SARS or SARS-like illnesses," Breiman added.

"We think they are involved in some way ... and there is a possible role for other animals including rodents."

TERRA.WIRE