Chapter 4
Cooperation with and assistence to Court in or outside South Africa
Part 2
Judicial assistance to court (ss 14-32)
32 Enforcement of sentence of imprisonment
(4) (a) Subject to paragraphs (b) and (c), the provisions of the Correctional Services Act, 1998, and the domestic law of the Republic apply to a person contemplated in subsection (3).
(b) The sentence of imprisonment referred to in subsection (1) may only be modified by the relevant authorities in the Republic at the request of the Court, as a result of an appeal by the person serving the sentence to, or review by, the Court in terms of the Rules.
Non-modification of sentence by State
Periodical review by ICC regarding reduction of sentence
EDIT.