South Africa High Court Judge Piet Koen has rejected a request by former President Jacob Zuma to remove a senior prosecutor from this trial for corruption and racketeering.
In his application Mr Zuma had accused Billy Downer of being biased against him and leaking his private medical records to the media – claims that were not proven.
The former president has avoided prosecution for almost two decades over charges of allegedly receiving kickbacks from French arms company Thales relating to a $2bn weapons contract.
Both Mr Zuma and Thales have denied the charges.
Judge Piet Koen found that there was no basis to claims made by Mr Zuma that he would not have a fair trial unless Mr Downer was removed.
Mr Zuma’s legal team has said it intends to appeal against the latest ruling in a higher court.