After more than a decade of legal wrangling, South Africa's biggest alleged foreign exchange manipulation case has moved a significant step closer to trial.

After more than a decade of legal wrangling, South Africa's biggest alleged foreign exchange manipulation case has taken a major turn — though not in the direction the Competition Commission had hoped.

The Constitutional Court handed down judgment on Tuesday in the long-running case against several global and local banks, finding against the Commission on most points while upholding its appeal in relation to only two respondents.

The judgment does not determine whether the banks manipulated the rand or contravened the Competition Act — that question now falls to the Competition Tribunal, but for a far smaller pool of banks than the Commission had hoped to take there.

As the court noted, the Commission's accusation was that the banks "colluded to manipulate the exchange rate between the United States Dollar (USD) and the South African Rand (ZAR)".