Former South African President Jacob Zuma on Monday continued with legal proceedings to remove the prosecutor in his corruption case.

Zuma and his legal team, led by Advocate Dali Mpofu, are challenging Judge Piet Koen’s ruling last year that dismissed Zuma’s bid to have Billy Downer recused from prosecuting the arms deal corruption trial.

Zuma’s lawyers are appealing the court’s ruling, saying Billy is biased and unfit to lead the prosecution. They are also accusing Downer of leaking documents related to his case to the media.

Zuma is facing corruption charges linked to the country’s controversial 1999 arms deal in which he is alleged to have received bribes from French arms manufacturer Thales through his financial advisor Schabir Shaik, who has already been convicted of corruption for that transaction.