Zuma, 79, was sentenced in June to 15 months in prison for contempt of court after ignoring instructions to participate in a corruption inquiry.

He handed himself in to begin his sentence on July 7, triggering some of the worst violence South Africa had seen in years. Anger from supporters snowballed into broader outrage over hardship and inequalities that persist 27 years after the end of apartheid.

He began medical parole in September, but earlier this month South Africa's high court ordered that decision void and that he should return to jail - raising concerns about further violence. read more

That same court ruled on Tuesday his legal team should be able to appeal against the judgment at a higher court.

"In my view, this matter merits the Supreme Court of Appeal's attention," Judge Elias Matojane said.

He added there was a reasonable possibility another court may rule differently on the issue of whether Zuma's time on medical parole should count towards his sentence. Matojane previously ruled it should not.

The legal processes against Zuma for alleged corruption during his nine-year reign are widely viewed as a test of post-apartheid South Africa's ability to enforce the rule of law, especially against powerful, well-connected people.

Zuma's 2009-2018 presidency was marred by widespread allegations of graft and wrongdoing, and he faces a separate corruption trial linked to his sacking as deputy president in 2005 when he was implicated in a $2 billion arms deal.

He denies wrongdoing in all cases and says he is the victim of a political witchhunt.

Reporting by Emma Rumney; Editing by Kevin Liffey and Nick Macfie