IDAC head Advocate Andrea Johnson faced intense scrutiny at the Madlanga Commission as her credibility and decisions came into question amid ongoing corruption investigations.

Questions over the credibility of key witnesses and the legality of key investigative decisions dominated this week's Madlanga Commission hearings, with Independent Directorate Against Corruption (IDAC) head Advocate Andrea Johnson coming under sustained scrutiny before the inquiry concluded with arguments over North West businessman Suliman Carrim's fifth application to postpone his testimony.

Over four days, Johnson faced sustained questioning over decisions taken by IDAC, her interpretation of the law, and inconsistencies between evidence she gave before Parliament's Ad Hoc Committee on the SAPS inquiry and her testimony before the commission.

Commissioners also examined whether IDAC acted within its statutory powers when investigating and arresting Crime Intelligence head Lieutenant-General Dumisani Khumalo and other senior officers.

The week concluded on Friday with Commission Chairperson Justice Mbuyiseli Madlanga reserving judgment after hearing competing arguments over whether Carrim should receive an open-ended postponement on medical grounds or return to testify on a fixed date following an independent medical assessment.