Hong Kong authorities confirmed Thursday that a dead bird found in the southern Chinese territory had tested positive for the H5 strain of the bird flu virus.
A government spokeswoman told AFP that laboratory tests had confirmed the highly decomposed chicken carcass found on the seashore of an island in the territory on December 18 carried the deadly strain.
In a press release a spokesman said the Hong Kong government was "concerned about the incident and will continue to monitor the situation".
There were no poultry farms within three kilometres of the shore and there was no evidence of backyard poultry in nearby villages, the statement added.
The government will step up inspections of the shore and its immediate vicinity, the statement said.
Officials did not raise the city's public health warning on bird flu.
In November, Hong Kong confirmed its first human case of bird flu since 2003, after a 59-year-old woman tested positive for Influenza A (H5), a variant of bird flu.
At the time, the government raised its avian influenza alert level to "serious", but it has been lowered since.
Hong Kong was the site of the world's first major outbreak of bird flu among humans in 1997, when six people died of a mutation of the virus, which is normally confined to poultry.
Millions of birds were culled in the 1997 outbreak.
Six years later the city was gripped by a full-blown panic when the deadly respiratory disease SARS emerged, killing about 300 people.
Public anxiety returned to the city of seven million people last year with an outbreak of swine flu that claimed about 80 lives.