JOHANNESBURG, Nov 23, 2022 (BSS/AFP) - A South African court ruling that found former president Jacob Zuma was unlawfully granted medical parole and ordered his return to prison to complete his sentence, is "cruel" and "degrading", his representatives said Tuesday.

Zuma, 80, had been handed a 15-month term in June 2021 for contempt of court, a move that triggered deadly unrest.

But he served only two months before being given parole for medical reasons that remain unclear.

Parole was granted by the head of South Africa's prison service, despite an opinion by the service's medical committee that Zuma did not meet the required conditions.

On Monday the Supreme court of appeal ruled that the parole was "unlawful", that Zuma had not finished serving his sentence and must return to jail.

In a late night statement, Zuma's foundation described the court's decision as "an act of injustice. It is nothing but an exercise in cruelty and degrading punishment".

The prison authorities last month announced that Zuma's 15-month term was formally over.

"On what legal basis can an expired and fully served sentence be resurrected from its grave by a court of law?" the foundation asked.

"To impose further imprisonment after the expiry of a jail term is totally unheard of and it is indeed a textbook case of judicial overreach," it added.

A prominent figure in the fight against apartheid, Zuma became president in 2009. He was jailed for refusing to testify to a high-level inquiry into massive state corruption that unfolded under his presidency.

He was forced to step down in disgrace by the ruling ANC in 2018 following mounting corruption allegations.

When his jail term was announced, violent protests broke out that spiralled into looting, leaving 350 people dead.

Zuma still has the option of approaching the Constitutional Court, the highest judicial instance in the land, to appeal the latest ruling.