A military officer, a park ranger and an employee of the prominent NGO Wildlife Conservation Society were shot dead on Tuesday as they were leaving Keo Seima Wildlife Sanctuary in Mondulkiri province, national police spokesman Kirth Chantharith told AFP.
He said police suspected Cambodian border forces, who were assigned to investigate a stolen chainsaw, were responsible for the killings.
“We suspect it was them who fired” on the group, Kirth Chantharith told AFP, declining to elaborate further.
Authorities are still investigating the incident and searching for suspects, he added.
Keo Sopheak, head of Mondulkiri’s environmental department, confirmed the deaths and said the group was killed about five kilometres away from where they seized the chainsaw from eight loggers near the Vietnamese border.
Illegal logging is rampant in Cambodia, with demand for rare wood in China and Vietnam driving rapid deforestation that has plundered a quarter of the country’s forests in a generation.
Cambodia’s forest cover has fallen from 73 percent in 1990 to 46 percent in 2013, according to the United Nations.
The illicit timber trade thrives on weak rule of law in remote areas and with pliant forestry officials and security forces, some of whom are employed by illegal loggers for protection.
But forests are also under threat through government-approved land clearance deals for everything from rubber plantations to hydropower dams.
Several high-profile killings of environmental activists in recent years have underscored the dangerous work carried out by conservationists.
In 2015 a forest ranger and a policeman who were investigating illegal logging in Cambodia were killed and at least 10 people, including a soldier, were arrested over the murders.