The dried carcasses of eight rare primates have been confiscated in the southern province of Binh Phuoc, director of the Bu Gia Map National Park said Monday.
Nguyen Dai Phu said the carcasses were of black-shanked douc langurs (Pygathirix nigripes) were found last week in a tent erected by poachers near the park, he added.
Inspectors also arrested 32-year-old Sung A Chu in the tent, but two others escaped, leaving behind guns and langurs, Phuc said.
All the animals had been shot dead, Phu said.
Inhabiting forests in Vietnam and Cambodia, the primates are listed as an endgangered species by the International Union for Conservation of Nature (IUCN).
In August 2008, the Wildlife Conservation Society had reported that 42,000 black-shanked douc langurs have been found in Cambodia's Seima Biodiversity Conservation Area the largest known population of the endangered species.
Previously, Vietnam was considered home to the largest population of the langurs estimated at around 600.
However, no definitive figures are available for the total current population of the species which are hunted for traditional medicine purposes.