Separatist leader Nnamdi Kanu on Monday refused to defend himself against terrorism charges, telling a Nigerian court there was no valid case against him and demanding immediate release.

Kanu, a British citizen and leader of the banned Indigenous People of Biafra (IPOB) movement, told Justice James Omotosho he had reviewed the case file and found no legal basis for the prosecution.

Kanu faces seven charges - ranging from terrorism to knowingly broadcasting falsehoods - stemming from his campaign for the secession of southeastern Nigeria. He denies any wrongdoing.

"There is no extant law in this country upon which the prosecution can predicate the charges against me," he said.

Kanu also said he was withdrawing a plan to call 23 witnesses, including two Americans, to testify in his defence.

Justice Omotosho instructed Kanu to submit a written address outlining his position to the prosecution. He advised the defendant to consult legal experts on the implications of his decision. The court adjourned the case until November 4.

Kanu was first arrested in 2015 but disappeared from Nigeria while on bail in 2017.

He was subsequently arrested in Kenya in 2021 and extradited.

His trial has drawn international attention and sparked protests across southeastern Nigeria, where IPOB enjoys significant support.

An attempt by the region to secede as the Republic of Biafra in 1967, the year Kanu was born, triggered a three-year civil war that killed more than 1 million people.