Mayor Herman Mashaba on Wednesday said he had referred himself to the Council Ethics Committee following allegations that he hired a financial expert employed by his wife's firm to do a presentation on benefits of insourcing, which would result in the cancellation of some contracts.

Mashaba said in response to reports alleging wrong-doing, the mayor said: "I have taken the extraordinary measure of referring the matter to the council of Johannesburg’s Ethics Committee".

Reports doing the rounds suggest that Mashaba's move to bring in a financial expert known to him was a conflict of interest even if the person was not paid for the presentation.

"I believe I have responded to the matter sufficiently, I have committed to run the City of Johannesburg whilst holding myself to the highest ethical standards. It is time that citizens believe in their political leadership, and this can only happen when we set the bar higher," said the mayor who is a member of the Democratic Alliance.

On Tuesday Mashaba told a radio station that the reports were being driven by people linked to the African National Congress, which he claims benefits from contracts gained through "outsourcing". He said these contracts would soon be cancelled. Mashaba said this move would save the council millions of rand and enable it to raise salaries of workers.

Mashaba on Wednesday said he has written a letter to the Speaker of Council Cllr Vasco Da Gama requesting a probe into allegations of "conflict of interest".

"There was no conflict of interest, it was not an unsolicited bid and no advantage or benefit was derived. It was a dedicated South African willing to give of their time, free of charge, to the benefit of our City," said Mashaba.

"The simple truth was that this move to insource security guards in the City caused a lot of unhappiness in the circles of the politically connected few who have made a fortune from the over 90 security contracts that the City has held valued at R640-million."

Mashaba said he will subject himself to any investigation that is required to protect the image of Johannesburg.

"In light of public interest in this matter, I have also informed the Speaker of my decision to waive my rights to this matter being treated confidentially and I would welcome the process being conducted openly," the mayor said.

"Unlike what we have seen across our country, political leaders with nothing to hide must step forward and be fully accountable to their residents."