The Asian Human Rights Commission is adding its voice to concerns at the death of West Papua separatist militia leader, Danny Kogoya.
Mr Kogoya died in hospital in Vanimo in Papua New Guinea last week, reportedly of liver failure due to the presence of unusual chemicals in his body.
A doctor in Vanimo has suggested poison was administered while Mr Kogoya was a patient at the hospital - he had been there receiving treatment.
A year earlier Mr Kogoya had been shot by the Indonesian military which subsequently amputated his leg, an operation for which he had not given permission.
The death has been officially classified as a murder and the court in Vanimo last week ordered that an autopsy to be carried out.
But the Commission says Indonesian officials are preventing the hospital in Vanimo from going ahead and it says this raises suspicions of Jakarta's involvement in Mr Kogoya's death.
The Commission has called for a letter writing campaign to put the issue before political leaders in Indonesia and PNG.
