Public Enterprises Minister Pravin Gordhan will appear before the Public Protector on Wednesday.
Busisiwe Mkhwebane says she resorted to serving a subpoena on the minister as he ignored her requests to appear.
Gordhan is expected to answer questions relating to the granting of early retirement to Ivan Pillay, the former deputy commissioner of the South African Revenue Service.
And his subsequent re-employment in 2010.Gordhan was finance minister at the time. Mkhwebane, however said the meeting would be private.
“Adv. Mkhwebane wishes to indicate that the meeting will not be open to the media. The meeting is part of a normal investigation process. The Public Protector does not investigate such matters out in the open as that might jeopardise the investigation,” her office said in a statement