National Treasury has argued that the alleged actions of banks to manipulate the dollar-rand exchange pair from 2007 to 2013 were not the main cause of the local currency substantially losing its value over the past decade, or the economy being in the doldrums. Rather, problems such as Eskom blackouts and the logistics crisis are to blame.

South Africa's commercial banks have delivered a spirited defence against allegations of currency manipulation and market collusion, saying there is no evidence against them in the Competition Commission's eight-year case.

Meanwhile, National Treasury has argued that the alleged actions of 28 banks to manipulate the US dollar-South African rand exchange pair from 2007 to 2013 were not the main cause of the local currency substantially losing its value over the past decade or the economy being in the doldrums.

Treasury said if the banks were to be found guilty of artificially influencing the currency pair by the Competition Tribunal, which acts as a court on antitrust matters, it would "indicate the prevalence of poor market conduct practices" at the time of the pernicious behaviour.

The alleged behaviour of currency traders belonging to the 28 implicated banks would have affected individual clients of the banks, as they -- rather than the country and its economy -- would have directly felt the pain of slight movements in the exchange rate, Treasury said.

"It [the alleged wrongdoing of banks] would not have influenced the depreciating trend of the currency since 2013, the level of which is driven by broader changes in the global...