Updated

Cambodian military police say there will likely be no further investigation into the shooting death of a prominent environmentalist because the officer who shot him then took his own life.

Military police spokesman Kheng Tito says In Ratana shot Chut Wutty, the director of the National Resources Protection Group, after the two men argued fiercely Thursday, then fatally shot himself when he learned his victim was dead.

Kheng Tito had said Chut Wutty shot the officer, although it was unclear who fired first. He said Friday that the case would be closed and that further investigation was unlikely because the perpetrator had died.

Human rights and environmental groups have called for a probe into the killing of Chut Wutty, who was investigating illegal logging with two journalists.