Prosecutors have requested the Dong Nai Culture and Nature Reserve to take measures against park rangers who failed to stop poachers from transporting meat from an endangered gaur (Bos gaurus) out of the reserve on February 26.
There were no personnel at the rangers station in Ma Da Forest when three poachers went past it, they said.
Prosecutors are also filing charges of violating regulations governing the protection of precious and rare wild animals against the trio of Le Nguyen Anh Hung, 21, Le Minh Tien, 32, and Pham Thanh Liem, 15.
But Liem will escape criminal charges because he is underage.
According to investigators, Hung and Liem went hunting in the reserve with a homemade gun at around 9 p.m. on April 26.
After finding a herd of around 10 gaur near a waterhole, Hung shot a female aged around two. The 200-kg animal ran for a short distance before collapsing.
The duo informed Tien and they slaughtered the bovine in the forest. They drove out of the forest on two motorbikes, passing the rangers station at around 3 a.m. after finding out there was no one there.
They sold 51kg of meat to a woman in the southern province of Binh Phuoc for VND6.1 million (US$273).
Police arrested Hung and Liem on March 11. Tien turned himself in two days later.
Prosecutors said the park rangers’ dereliction of duty made it easy for the trio to transport wildlife meat out of the forest and caused difficulties in the investigation.
Conservationists estimate there are around 500 wild gaurs in Vietnam, including 300 in the more than 100,000-hectare (247,100 acres) Dong Nai Culture and Nature Reserve.
The number has shrunk from more than 3,000 in the 1970s, mostly due to poaching.
Hung and Liem face jail terms of up to seven years or a fine of up to VND500 million ($22,500).