Police in the Indonesian province of Papua have arrested 12 people over the murders, in 2002, of two US teachers and their Indonesian companion.
The three victims were ambushed and shot dead in Timika near the US-owned Freeport gold mine where they worked.
The Jakarta Post reports that Anthonius Wamang, who was indicted by a US grand jury in 2004 following an FBI investigation, is among those being held.
Local police say they suspect all 12 detainees are members of the separatist Free Papua Movement.
However rights groups suspect the Indonesian military was involved in the killings but that such allegations have never been properly followed up.
Eight of the detainees, including Mr Wamang, have been flown to the provincial capital Jayapura for questioning.
A police spokesman said the other four would also be flown there later.