President Salva Kiir has fired his Press Secretary Ateny Wek Ateny, in a presidential decree on Friday evening.
No reason was provided for his dismissal, and no immediate replacement has been appointed.
Ateny, a former vocal critic of President Salva Kiir and the system, was appointed in November 2013.
He now leaves the position as one of the longest serving officials, having survived years of relentless presidential decrees.
Before his appointment, Ateny was a political commentator at the now defunct Citizen Newspaper.