Two Cambodian police officers and a soldier were arrested Monday in the murder of a journalist who was investigating illegal logging, local media reported.

The body of Taing Try, 47, was discovered Sunday shot in the head in north-eastern Kratie province, where he was investigating reports that oxcarts had been delivering hardwood lumber to a warehouse at night, The Cambodia Daily reported.

The warehouse was owned by the area's military police chief, it said.

An SUV found upturned with no registration plates near the scene, thought to be the getaway car, was traced to a local police officer, a military police officer and a soldier from Cambodia's Royal Armed Forces, the report said, prompting their arrests.

Try had been travelling in a Toyota Camry with another journalist, who walked to a nearby farm when their car got stuck, and found him dead by their car when he returned with help.

"This cold-blooded killing shows again just how dangerous Cambodia is for journalists, especially those who investigate wrongdoing about the country's land and forests," Phil Robertson, deputy director of Human Rights Watch's Asia division, told the Daily.

Ten journalists have been murdered in Cambodia since 1993.

Hang Serei Oudom, a reporter who had been investigating illegal logging in the noth-eastern province of Rattankiri was murdered in 2012, the same year environmental activist Chut Wutty was killed while travelling with two Cambodia Daily reporters in Koh Kong province.

The three men arrested for the latest murder have confessed to the crime and will be tried, The Daily reported.