A South African court Wednesday ordered former president Jacob Zuma to return to prison, cancelling the medical parole he was granted in September.

The decision to place Zuma on medical parole is “declared unlawful and set aside”, read the ruling by High Court Judge Elias Matojane.

Zuma, 79, was jailed in July for 15 months for contempt of court, after he refused to give testimony to corruption investigators. His jailing sparked violent protests and looting in his home province of KwaZulu-Natal that spread to the financial hub Johannesburg in July, claiming over 350 lives.

That was the deadliest violence in South Africa since the end of white-minority rule in 1994. The current President, Cyril Ramaphosa, has described the unrest as an orchestrated attempt to destabilize the country.

Zuma was granted medical parole on September 5, but the exact reasons were never revealed. While in prison, he was taken to hospital for surgery to treat an undisclosed ailment.

Zuma can appeal the recent court decision.