South Africa's former President Jacob Zuma has accused the judiciary of not trusting a medical report by military doctors.

The former president has refused to undergo a medical examination by doctors selected by the prosecuting authority.

The military doctors are responsible for the health of all former presidents and have already filed a confidential report on his fitness to stand trial.

Mr Zuma's foundation spokesperson Mzwanele Manyi told ENCA television that the former head of state was tired of his health being doubted.

Mr Zuma has been serving a 15-month sentence since July for defying a court ruling compelling him to testify in a corruption inquiry.

He was admitted to hospital outside prison earlier last month and underwent a surgery.

He had been due to face a separate trial on corruption allegations - which was postponed to this month.