Amnesty International says former prisoner of conscience Yusak Pakage is being denied access to medical treatment while in police detention in Papua province, Indonesia.
It says he has reportedly been threatened with torture and has not had access to a lawyer since his arrest.
According to sources he is suffering from stomach pains and has not been able to eat.
Mr Pakage was arrested on the 23rd of July during the trial of Papuan political activist Buchtar Tabuni.
Police arrested Mr Pakage after they found a pen-knife in his bag.
He was later charged under Emergency Regulation 12/1951 for possession of a weapon, which carries a maximum sentence of ten years' imprisonment.