Researchers at the University of Hong Kong hunting for the source of the human SARS virus have found a close relative of the disease in Chinese bats.

The team has urged caution in handling the mammals: bat meat is regarded as a delicacy in parts of Asia, and their droppings are used in traditional Chinese medicine.

The coronavirus has previously been found in civets, weasel-like animals that are widely sold in live-animal markets. Chinese health officials had suspected that civets act as a reservoir for the virus - displaying no symptoms themselves, but housing the disease and passing it on.

However, other research has suggested that another species may be the original host prompting the University of Hong Kong's Kwok-yung Yuen to lead a study of wild animals in the Hong Kong countryside that could come into contact with civets.

He found a coronavirus (CoV) very closely related to the SARS-CoV in around 40 per cent of wild horseshoe bats that he examined. Genetic analysis also suggests that the Bat CoV probably shares an ancestor with the version carried by civets.

The team was not able to determine how the bats became infected, and could not say if they are responsible for spreading the disease to other species, including the civets. ®