South Africa’s Supreme Court of Appeal ruled on Monday that the decision to release former President Jacob Zuma on early medical parole was “unlawful” and that he should return to prison to finish his sentence for contempt of court.

Zuma was sentenced last year to 15 months imprisonment after ignoring a court order to testify at a government inquiry into widespread corruption during his almost decade as president that ended in 2018 when incumbent Cyril Ramaphosa replaced him.

Zuma was released on medical parole in September 2021 after only serving a fraction of the sentence. But in December, the high court set aside the parole decision and ordered him to return to jail.

Zuma appealed that ruling and judgement was delivered on Monday after the department of correctional services said in October that his prison sentence has finished.

“In other words, Mr Zuma, in law, has not finished serving his sentence. He must return to the Escourt Correctional centre to do so,” the Supreme Court of Appeal judgement read.

The court took issue with the department’s claim that Zuma’s sentence had ended when the appeal was still being heard.

It also found that the decision by the former national commissioner of correctional services to grant Zuma medical parole against the advice of the Medical Parole Advisory Board, a specialist body, was unlawful.

“On any conceivable basis, the commissioner’s decision was unlawful and unconstitutional. The high court was correct to set it aside,” the judgement said.

The Jacob Zuma Foundation did not immediately respond to a request for comment, while a spokesperson for the department of correctional services said the judgement was being studied and it would likely respond later.