The Public Service Commission (PSC) has agreed to probe Fisheries Minister Tina Joemat-Pettersson's controversial appointment of a senior manager, the DA said on Friday.
The minister appointed Greta Apelgren-Narkedien as a deputy director general (DDG) in the department in December.
In March, Apelgren-Narkedien admitted during an interview on Carte Blanche that the position of DDG was not advertised and that she was appointed without undergoing an interview process.
Joemat-Pettersson came under fire for the move, but insisted the process was above board as President Jacob Zuma had signed a presidential minute sanctioning the appointment.
In May, the department announced Apelgren-Narkedien had resigned to take on another job as head of the human settlements department in KwaZulu-Natal.
"Even though she has since vacated the position, the procedures around her appointment still requires investigation," Democratic Alliance MP Pieter van Dalen said.
Van Dalen said a written parliamentary reply by Public Service and Administration Minister Lindiwe Sisulu on the procedural requirements for appointing a DDG proved that Joemat-Pettersson acted illegally.
Sisulu's reply revealed that Cabinet adopted a set of protocols governing the appointment of department heads and DDGs in October last year.
"Among other procedures, these regulations required that a selection committee be convened to shortlist and interview prospective candidates," Van Dalen said.
The PSC had indicated it would finalise the investigation by August 16 and make the findings available.
"The DA looks forward to the outcome of the report and trusts that it will recommend stringent punitive measures against the minister," Van Dalen said.
"The people of South Africa deserve the best possible and qualified candidates for top positions in order to ensure optimum service delivery."