Six policemen have been shot dead at an outpost in southern Afghanistan.
Their bodies reportedly were discovered near their checkpoint late on June 12.
Omar Zwak, a spokesman for the governor of Helmand Province, said the next day that the men were killed by another police officer, who is now missing.
Some reports say two police officers are missing.
The Taliban said a policeman was recruited by them for the attack.
Local officials told RFE/RL they are investigating whether that is true.
If so, it would be another in a series of recent insider attacks among security forces in Afghanistan.
Last month, an Afghan soldier turned his weapon on two U.S. marines and killed them.
Last week, an Afghan police officer killed seven of his colleagues in Helmand.
With reporting by dpa, AP, and BBC