Gigaba also said on Friday his deputy Sifiso Buthelezi would join the bank as the alternate governor.
The minister’s confirmation comes a week after Mboweni complained on social media he was fired by the government. But in a statement the National Treasury said Mboweni’s term of two years as a board member of the Brics Bank had expired.
Mboweni wrote on Facebook that despite his contract expiring at the beginning of last month, it was a renewable contract and the government did not renew it.
Treasury said its director-general Dondo Mogajane will take over the position held by Mboweni at the bank.
“The nomination of Mogajane by Gigaba and subsequent appointment will ensure that no additional costs are incurred by government in remunerating an appointment from outside of public service while also enhancing strategic alignment and collaboration between the government and the bank,” the Treasury said.
It added that Mboweni’s contract was for two years and it ended last month.
Treasury said that the appointment of Mogajane, Buthelezi and Treasury deputy director-general Monale Ratsoma as an alternate board member was in line with the practice of other Brics member states to appoint government officials in the bank.
Buthelezi will serve in the bank as the alternate governor.
Mboweni has been outspoken in recent times and when Public Protector Busisiwe Mkhwebane released her report in June recommending the central bank's powers be clipped by Parliament, he warned against this.
Mboweni had said the Sarb’s independence must be protected as is done in many other countries.
This was critical for the market and financial stability in the country.
President Jacob Zuma will next week Thursday formally open the Brics regional office in Joburg.
When he fired Nhlanhla Nene as finance minister in December 2015, Zuma said he would head the Brics regional bank, but Nene never got the job. He has since joined the private sector.
The regional office will provide funding for projects on the African continent.