JOHANNESBURG: President Cyril Ramaphosa on Monday slammed attacks on South Africa's judiciary after his beleaguered predecessor Jacob Zuma, under scrutiny for alleged graft, accused judges of political bias.

Zuma, 78, has repeatedly snubbed a judicial panel probing the plunder of state coffers during his 2009-18 rule.

He risks jail time if found guilty of contempt of court for ignoring last week a Constitutional Court order to appear before the panel.

In a 12-page statement last week, Zuma accused the panel's chair, Deputy Chief Justice Raymond Zondo, of "political propaganda."

"Some judges... have assisted the incumbent president to hide from society what on the face of it seem to be bribes obtained in order to win an internal ANC election," he added, without giving names.

Ramaphosa said such attacks, without evidence or being referred to relevant authorities, were "deeply disturbing" and could erode trust in the judiciary and constitutional order.

"We should... be concerned when those who occupy prominent positions in society make statements that demonstrate a disdain for the basic principles of our constitution and the institutions established to defend our democracy," said Ramaphosa in his weekly newsletter.

Ramaphosa said the attacks should not be taken lightly and warned those who make them of possible consequences.

There has been a growing push, including from within ruling African National Congress (ANC), to compel the ex-leader to obey court orders.

ANC's top leadership is reportedly lining up a meeting with Zuma to resolve the impasse with the anti-graft commission.

On Tuesday he is due in court for a unrelated another corruption case dating back more than 20 years, when he was deputy president, and in which he is accused of taking bribes of four million rand ($220,000/200,000 euros) in a $3.4-billion arms deal with French aerospace giant Thales.

Zuma was forced to resign in 2018 over mounting graft scandals.