Four FBI agents are in Indonesia's Papua province to probe the killing of two American teachers there last year.
The deaths, which occurred when a van carrying employees of the giant Freeport gold mine was ambushed, remain unresolved, amid accusations the Indonesian military was involved.
The army, which provides security at the mine site, has blamed separatist rebels for the attack and repeatedly denied any role, but human rights groups say the military was behind the attack.
It is the third time an FBI team has been to the province to investigate the case which has put relations between the Indonesian military and foreign facilities in the vast country under the spotlight.
Because of the shooting, the U.S. Senate has cut off a military training assistance package scheduled to be paid next year.