The dead body of a man killed and cut into pieces was found on a road between Tonj Civil Hospital and Truth Ministry Clinic on Tuesday morning.
Neighbours of the deceased say they did not hear any noise at night, Radio Don Bosco reports.
Police have suspected the wife of the deceased man to have known the death of her husband.
Manheim Bol, the Deputy Governor of Tonj State says the state government has set a security committee to find out the circumstances of the killing.
The suspected wife is already under police custody, the Deputy Governor says.
Mannheim says general security situation in Tonj State is normal.
Communities have accepted peace, he says.
Remain calm and allow the security personnel to investigate about the killing of the man, the Deputy Governor advises the citizens of the area.