The teams say although more evidence links the human and civet forms of the virus, direct infection remains unproven Scientists who have provided fresh evidence linking the Sars coronavirus to civet cats in Guangdong's wet markets have stopped short of calling for a ban on the animal trade, instead urging better monitoring. Denying they had back-pedalled on their earlier stance, the Hong Kong and Guangdong scientists said they had modified their opinion based on new data, described in a online report by Science magazine yesterday. Tests by the scientists showed the animals - civet cats and a raccoon dog - had a coronavirus that was 99.8 per cent genetically identical to that found in humans, suggesting the virus had crossed the species barrier. 'Our findings suggest that the markets provide a venue for the animal [Sars coronavirus-like] viruses to amplify and transmit to new hosts, including humans, and this is critically important from the point of view of public health,' the team of 18 from Hong Kong University, the Department of Health and Guangdong's Centre for Disease Control and Prevention concluded in the Science report. Guan Yi, a gene-sequencing expert at the University of Hong Kong and the lead investigator, said: 'Our investigation clearly shows that the Sars-like virus comes from the Sars-like virus in the wild animal market. '[But] we have no direct evidence that those viruses in the markets can attack humans directly.' Another member of the team and chair professor of the department of microbiology, Yuen Kwok-yung, said: 'We have shown very clearly and concretely that it is from wild animals, especially from civet cats. There is some evidence that it is infecting humans, but we cannot be 100 per cent sure that it is directly the cause of the outbreak. 'We are not back-tracking. We based this on new findings and we modified our opinion accordingly.' Dr Guan and Zheng Bojian, an assistant professor at HKU, went to a Shenzhen wild animal market on May 7 and sampled eight species of wild and domestic animals, including the Himalayan palm civet, hog-badger and beaver. They also tested 1,500 people for the virus. Four out of six civets and one raccoon-dog had the Sars coronavirus, they said. The team also showed that eight of 20 wild-animal traders, three of 15 slaughterers and one of 20 vegetable sellers tested positive for antibodies to the Sars virus, showing they had been exposed to the virus. But two legislators questioned the scientists' position, saying it would be better to be safe than sorry, reiterating that a mainland ban on trading in animals should not have been lifted recently. Lo Wing-lok, the legislator for the medical sector, said: 'There is now more evidence that the virus from civet cats closely resembles Sars [in humans]. 'If that is the case, and we are more confident of the link, I would err on the side of overcaution than be complacent. I am still for the ban.' Fred Li Wah-ming, who chairs the Legislative Council's food and hygiene panel, said the ban should have continued and the Hong Kong government should hold talks with Guangdong counterparts to educate people not to eat wild animals. But a mainland forestry administration official said civets would not be banned again unless there was strong scientific evidence to do so, adding: 'If you have such evidence backed by an authoritative scientific organisation, please pass it to us so that we can take action.' Last month, the forestry administration released a list of 54 animals, including the masked palm civet, that can be traded and made use of provided they meet health and food regulations and were raised on farms.