The commission's two-year investigation found that the banks were involved in price fixing and market allocation regarding the South African rand and the USA dollar since April 2015.

Bank of America, JPMorgan, Standard Chartered, Commerzbank, Macquarie Group, Australia & New Zealand Banking Corp, Standard Bank Group, HSBC and BNP declined to comment when contacted by Bloomberg.

The ANC said it will closely follow the developments in this case and calls for the Competition Tribunal to level against the banks the harshest possible sanction where they are found guilty.

The South African Competition Commission said in a statement that it found that from at least 2007, "the respondents had a general agreement to collude on prices for bids, offers and bid-offer spreads for the spot trades in relation to currency trading involving USA dollar/rand currency pair".

Cardo's statements follow the announcement by the Competition Commission that it has referred a case to the tribunal for prosecution for alleged price-fixing against 17 banks, including three of South Africa's largest banks.

The Competition Commission on Wednesday said banks including Investec Ltd.

Feb 16 South African banks accused of rigging rand currency dealing should be punished if a report by the competition watchdog is true, the National Treasury said on Thursday. "The fact that some banks may have been partly responsible for the weak and volatile rand through currency manipulation is deeply troubling", the organisation said on Thursday. In particular, the foreign and local private monopoly and oligopoly structure of the banking and financial sector dominant in our country must be brought to an end, by means of, among others, strongly asserting developmental state ownership and co-operative banks and financial institutions.

Cardo said the party took collusion very seriously, as it works against fairness and opportunity but the ANC has already prejudged the outcome of the case, accusing the banks of a profit-driven assault on the Rand, fueled by nefarious agendas and politically motivated intentions.

Absa also said it will continue to co-operate with the Commission and pointed out that that the Competition Commission has not sought any penalties against Absa.

Investec, Standard Bank of SA and Absa Bank are among those involved.