For the first time since it was called into the case, the United States Federal Bureau of Investigation (FBI) is believed to be following several promising leads in the investigation into the slaying of two American teachers near the Papua mining town of Tembagapura in August 2002.

"They think they have leads to run this time," says one security expert familiar with the inquiry in the rugged Indonesian province.

Six FBI agents, the largest of the four teams to have visited so far, returned to Papua in late February. They are also staying for a month, longer than previous groups. The FBI was first called into the case soon after the murders. Despite devoting a lot of its resources to the war on terrorism, the FBI has prioritized the Papua investigation because Jakarta's failure to bring anyone to justice is having an adverse affect on relations between the US and Indonesia.

The US embassy has denied recent reports claiming that the bureau was now convinced military commanders had ordered the killings. In fact, the security expert says, one avenue the agents are pursuing is possible collusion between low-ranking soldiers and renegade elements of the Papuan separatist movement.