Gauteng Agriculture and Rural Development Member of the Executive Council (MEC) Nomantu Nkomo-Ralehoko stepped down on Friday, saying she took political responsibility for the controversy caused by her stolen official Mercedes-Benz.

In addition, the chief financial officer (CFO) who advised her during the process of purchasing the car has been suspended and a police case opened against her for investigation, the Gauteng provincial government said in a statement. The CFO would also face a disciplinary inquiry.

Simon Zwane, provincial government spokesperson, said he did not want to release the CFO's name because her arrest may be imminent.

"I sincerely regret this incident and apologise to the people of Gauteng. Consequently, I hereby step down as a MEC in the Gauteng Provincial Government," said Nkomo-Ralehoko in the statement.

Her resignation comes after The Star reported that a R920 000 Mercedes-Benz ML63 was purchased on her behalf for official use and then taken to her home in Tulisa Park on a Friday by her husband Sydney without insurance or a tracking device.

It was stolen the following day when robbers held her husband at gunpoint.

In response to enquiries by the newspaper, she explained that her husband was allowed to use her vehicle, and that she was permitted to take an official vehicle to her home.

In her statement she explained that, after moving into her office on May 13, her handover briefings included advice on how to acquire an official vehicle.

She said the CFO, and the director of facility management worked on arranging the purchase of the second-hand vehicle.

"On reflection of the events surrounding the purchase of the official vehicle, I realise that I was inappropriately advised, particularly by the CFO, on this process that led to the release of the vehicle without proper insurance and installation of tracking devices.

"In addition, the purchase of the vehicle and its subsequent theft raised suspicions which I think the government and the police must fully investigate."

She has opened a case at the Booysens police station for investigation of its theft.

"It has also come to my attention that the CFO did not obtain authority from the [head of department Stephen Cornelius] in this entire process. The CFO has now been suspended with immediate effect and a full investigation is underway.

"A criminal case has also been opened against the CFO by the department. I have since been made aware that there are other pending disciplinary cases in which the CFO is implicated in alleged financial misconduct."

Zwane said that a charge of financial misconduct had been laid against the CFO.

This was in terms of her alleged advice that the MEC may take delivery of the vehicle before insurance and a tracking device was arranged.

Zwane said this was a contravention of financial management rules.

The MEC continued: "The circumstances pertaining to the purchase of this vehicle, and its subsequent theft, have caused serious embarrassment to my family, the Gauteng Provincial Government and the African National Congress (ANC).

"I must state categorically that it was never my intention to circumvent any government procedure. Furthermore, I will never consciously seek to embarrass both the government and the ruling party.

"By stepping down I am signalling to our people that I hold them in high regard and further take political responsibility for things that have happened in the past week."

Zwane said Gauteng Premier Nomvula Mokonyane would still have to "apply her mind" to who would replace the MEC. The matter of recovering the lost taxpayers' money would probably be dealt with after the CFO's disciplinary hearing.

Spokesperson for the ANC in Gauteng, Nkenke Kekana, welcomed the MEC's resignation on Friday.

"We are encouraged that, right at the beginning of the term, the MEC and all other public servants will take responsibility if there is wrongdoing because it is not about them, but it's about serving the people of Gauteng," he said.