National Planning Minister Trevor Manuel will be retiring from government and Parliament this year, after he declined nomination for the African National Congress's national election list.
Manuel was speaking at the Ethics Institute's annual conference in Midrand.
He says he cannot understand why Brown -- who supported a probe into state capture -- would agree to reappoint Molefe.
On Friday it was announced that Molefe had resigned as an MP to return to his former post as Eskom CEO. There has been widespread outrage over his reappointment.