The head of the Independent Directorate Against Corruption (Idac), Andrea Johnson, has resigned.

She submitted her resignation letter, which was accepted by President Cyril Ramaphosa, to avoid a “costly and time-consuming” inquiry into her fitness to hold office.

“The allegations against me must still be proven but that will again require the setting up of a commission and a process which is both costly and time-consuming,” said Johnson in the letter to National Prosecuting Authority (NPA) head Andy Mothibi and Ramaphosa.

During her first appearance at the Madlanga Commission, Johnson asked to be allowed to refuse to answer certain questions linked to an allegation that she sent deputy head of crime intelligence Feroz Khan an assault case docket in which he was the suspect. The case is ongoing in court.

Johnson said she would not want to draw either the NPA or the Presidency into any court challenges. She said she wanted to exit with “as minimal disruption as possible”.

Johnson requested to be relieved from serving the three months' notice. While she had applied for retirement, she said that might be a subject of a legal battle regarding her fitness and pension, which would embroil the NPA, the Justice Ministry and the Presidency.

"This is a difficult request to make given the absolute love and commitment I have had for the position of being the Investigating Director of Idac," she wrote.

Johnson made concessions at the Madlanga Commission to the controversial arrest of the head of Crime Intelligence, Dumisani Khumalo.

Under tough questioning, she accepted that the Section 27 complaint laid by National Coloured Congress founder Fadiel Adams did not contain enough evidence to warrant the subsequent arrests of Khumalo and 12 other members in Crime Intelligence in June 2025.

Johnson further conceded before the commission that it was inappropriate to charge Khumalo’s recent hire, Brigadier Dineo Mokwele, as head of Technical Support Services as a “token appointment”. She also apologised for describing Mokwele as “unsuitable” for the role without seeing her qualifications and experience.

"The country cannot afford another commission," Johnson said, referring to a fitness-to-hold-office inquiry which would have probably arisen from a dismal performance at the Madlanga Commission.

“The NPA and Idac must and will always come first and I believe that this resignation in the manner proposed would serve the institutions and the country best,” she wrote.

“This in itself, let alone the attacks on me, does not sit well with me. I have given thirty years of service to an organisation I love dearly. I cannot be the reason that there is so much negative attention and reputational risk to Idac and the NPA,” she wrote.

Ramaphosa has accepted Johnson’s resignation and the request to vacate office with immediate effect.

“The President’s agreement follows a recommendation by Minister of Justice and Constitutional Development Mmamoloko Kubayi, and supported by National Director of Public Prosecutions Adv Andy Mothibi, that Adv Johnson’s request be granted,” said the presidency statement.

Although Johnson has tendered her resignation she remains under subpoena to testify at the Madlanga Commission. The commission has also subpoenaed all the case dockets related to the investigation she approved into Khumalo and members of the Crime Intelligence division.

The commission has requested that Johnson answer allegations of prosecutorial interference in targeting the leader of the political killings task team after receiving an email from suspended police minister Senzo Mchunu.

Johnson has been asked to answer about her evidence in alleging Khumalo abused the Secret Service Account.