Officials said the dead goose and two dead ducks that were found on Lantau Island last week contained the deadly H5N1 strain. The birds are believed to have washed up in Hong Kong after dying in China.
Around 20 other birds have been found in the past six days in Hong Kong, where private poultry farms have been banned since 2006. Officials suspect that all of the birds came from China, where five people died from the H5N1 virus in January.
In December, more than 90,000 chickens were culled at a Hong Kong poultry farm following a bird flu outbreak. Hong Kong's biggest bird flu outbreak was in 1997 when seven people died. The last death in the former British colony was reported in 2003.
Although there have been no incidences of human to human infection, experts fear that bird flu may mutate into a form that could easily be transmitted from person to person, causing a global pandemic.