AMNESTY international is calling on South Sudan government authorities to release businessman Karbino Wol Agok.
In a statement, the organization urges those involved in the incident to charge him with recognized criminal offence in accordance with the international Law.
They stress that Agok should not be subjected to torture or any other ill treatment while in detention.
Amnesty urges authorities to ensure the businessman is granted regular access to his family and healthcare.
It is also concerned of his health condition being held in solitary confinement for a more than two months.
Amnesty International says it documented numerous arbitrary detentions by the National Security Services in multiple facilities where detainees are often subjected to torture and other ill-treatments.