Many versions of where he was ‘intercepted’ up have continued to flood on social media with so many countries named.

But Emmanuel, in a statement on Wednesday, claimed his elder brother was arrested in Kenya.

He said: “My brother Nnamdi Kanu demands the right to self-determination for Biafra. Self-determination is the right that underpins the United Nations.

“Because Biafrans support Nnamdi Kanu’s call for Biafran self-determination, my brother has now been subjected to the most serious violations of international law.

“Whilst visiting Kenya, Nnamdi Kanu was detained and handed over to the Nigerian authorities who then flew him to Nigeria.

“My brother has been subjected to extraordinary rendition by Kenya and Nigeria. They have violated the most basic principles of the rule of law. Extraordinary rendition is one of the most serious crimes states can commit. Both Nigeria and Kenya must be held to account. I demand justice for my brother, Nnamdi Kanu.

“Nnamdi Kanu holds both British and Nigerian citizenship. Nnamdi Kanu is Biafran, not Nigerian. He has rejected his Nigerian citizenship.

“The British High Commission in Nigeria must insist upon my brother’s immediate release. They must guarantee his safety and security. Nnamdi Kanu must be returned home to the UK to his wife and his sons who live there.

“The Foreign Secretary, Dominic Raab, must make clear to the Nigerian authorities that they will not tolerate the unlawful detention of British citizens and the UK Government condemns the Nigerians and Kenyans for undermining the rule of law. Foreign Secretary Raab must be clear.

“There will be consequences for those who resort to extraordinary rendition. The British Government must insist upon justice for Nnamdi Kanu.”