The United States says it welcomes the arrest by Indonesian police of the Papuan Anthonius Wamang in an investigation into the killings of two American teachers and an Indonesian.
The three victims were ambushed and shot dead in Timika in 2002 near the US-owned Freeport gold mine where they worked.
Local police suspect Mr Wamang and 11 others detainees to be members of the separatist Free Papua Movement.
They're to be flown to the provincial capital Jayapura for questioning.
Mr Wamang was indicted by a US district court last July for the murders of the two Americans.
A spokesman for the US state department, Sean McCormack, says seeking justice for the crime remains a priority for the United States, and he's pleased that the Indonesian government also recognises the importance of this case.
President Susilo Bambang Yudhoyono met the widow of one the victims last May, and the Indonesian police and army have worked together with the FBI on investigating the case.
Rights groups suspect the Indonesian military was involved in the killings.