Conservationists say the critically endangered Javan rhinoceros is now extinct in Vietnam, after the last one was killed.
Experts blame poaching for the animal's demise since it had a bullet wound in its leg and its horn had been cut off.
The BBC says genetic analysis of rhino dung samples found they could all be traced to a single animal - the one that died in 2010.
The World Wildlife Fund says Vietnam's efforts to deter poaching have been inadequate.
The Fund says the voracious appetite in Asia for rhino horn for traditional medicines means the remaining Javan rhinos - less than 50 in number in a small national park in Indonesia - must be protected.
