A dead bird found in Hong Kong has tested positive for a milder strain of the bird flu virus, the city´s health authorities said.

"Preliminary testing of a dead bird ... has indicated a suspected case of H5 avian influenza," a spokesman for the Agriculture, Fisheries and Conservation Department said in a statement.

Further tests are now being carried out on the carcass of the Crested Hoshawk, which was found by a member of the public, the statement added.

Hong Kong was the scene of the world´s first reported major bird flu outbreak among humans in 1997, when six people died of a then unknown mutation of the avian flu virus. Millions of poultry were culled.

A renewed outbreak in 2003 among poultry flocks in Asia triggered a wave of infections worldwide.

The flu´s H5N1 strain is potentially deadly to humans. Bird flu has killed more than 150 people worldwide since late 2003. There are fears it could mutate and trigger a deadly human flu pandemic.