Cape Town — South Africa's former president, Jacob Zuma, is on his way to hand himself over to prison authorities, his foundation said late Wednesday.

In a statement issued on Twitter minutes before the deadline imposed for his arrest by South Africa's highest court, the JG Zuma Foundation announced that "President Zuma has decided to comply with the incarceration order" issued by the country's Constitutional Court last week.

"He is on his way to hand himself into a Correctional Services Facility in KwaZulu-Natal," the foundation added. "A full statement will be issued in due course."

The court ordered Zuma jailed for 15 months for refusing to obey a court order to appear before a commission of inquiry into the high-level government and private sector corruption which flourished during his presidency.

It gave him five days - until last Sunday night - to report to a prison, and ordered police to arrest him within another three days - by midnight South African time on Wednesday - if he failed to hand himself over.

Tensions and uncertainty rose around Zuma's homestead at Nkandla in rural KwaZulu-Natal province during Wednesday evening as it appeared he might resist arrest. His lawyers asked the province's High Court on Monday to suspend the Constitutional Court's order, but that court is expected to issue a decision only on Friday.

Zuma's lawyers will also appear before the Constitutional Court next Monday to ask the judges to rescind their order that he be jailed for contempt of court. However, as the country's apex court, its decision is final in South African law and the grounds on which it can rescind a decision are narrow. Constitutional lawyers rate his chances of success on Monday as slim.

However, it is unlikely that the former president will serve anything close to 15 months. Prisoners usually qualify for a one-third remission of sentence for good behaviour, and a remission of two-thirds can be earned.

In addition, the prison authorities are currently releasing older prisoners early because of the risks of Covid-19 infection. In May, Parliament in Cape Town was told 14,000 prisoners had been released under a special Covid-19 parole scheme. Zuma is 79 and has cited health issues in his bid to keep out of prison.

President Cyril Ramaphosa also has discretion to grant a pardon. While opposition politicians would raise an uproar in this event, such a step would send a clear political signal to those Zuma followers remaining in the governing African National Congress that Ramaphosa is firmly in charge of the party and the country.