The apex court overruled the judgment of a lower court that granted Kanu freedom from prison.
Kanu, the leader of the Indigenous People of Biafra (IPOB) proscribed by the Nigerian governor, had asked the Supreme Court to uphold an October 2022 judgment by the Court of Appeal.
The appeal court ordered his release from prison and described his extradition from Kenya in June 2021 as forceful.
The secessionist leader has been in prison since June 29, 2021, after his extradition by the secret police in collaboration with Interpol. He fled Nigeria following the invasion of his home in southeast Abia State and failed attempts to arrest him in 2017 by the army.
But the Supreme Court in its judgment written by Justice Garba Lawal, declined Kanu’s request for release. It also quashed a terrorism charge.
In September 2017, the Nigerian government obtained a court order that categorized the IPOB as a terror group and proscribed it.