The corpse of a finless porpoise with a slightly injured tale was found on Upper Cheungsha Beach on Thursday morning.
Police called in a team from the Hong Kong Ocean Park Conservation Foundation who confirmed it was a male, about 1.4 metres long, aged between juvenile and adult, Oriental Daily reported.
The porpoise appeared to be stranded on the beach, but Ocean Park vets who studied the body say they are not certain over the cause of death.
According to AFCD figures, around 20 Indo-Pacific finless porpoises are stranded on Hong Kong beaches each year.
The Ocean Park Conservation Foundation urges people to call 1823 if they find a stranded dolphin or porpoise.
[This story was updated to indicate that Ocean Park vets are unclear over the cause of death]
Photo: AFCD file photo