Nnamdi Kanu, leader of Indigenous People of Biafra (IPOB), a group which has been demanding secession of southeast Nigeria, a territory formerly known as Biafra, did not show up as his case resumed at the Federal High Court in Nigeria's capital, Abuja.
His absence has raised concerns among his ardent supporters who say they have not seen Kanu for weeks. "I don't know where my client is," Kanu's lawyer, Ifeanyi Ejiofor, said.
The home of the 50-year-old pro-Biafra leader was reportedly invaded by soldiers on September 14. "Since that time I have not heard from him. I cannot tell whether he is alive or dead," Ejiofor said.
Two weeks after Kanu's disappearance, a Reuters team reported that it had seen bullet holes and smashed windows during a visit to his house in Umuahia, the capital city of Abia State in southeastern Nigeria.
During the court's proceedings on Tuesday, Ejiofor hinted that his client is in the custody of the federal government. The case was adjourned until November 20 to allow for finding more information on Kanu's whereabouts.
Kanu, who was charged in October 2015 with conspiring to commit treason, was issued bail in April and released on medical grounds. However, the judge set strict bail terms which included not attending rallies, not being part of a crowd of more than 10 people, and not giving interviews during the bail period.
Kanu, however, has been vocally outspoken since his release, galvanizing Igbo people who are calling for the separation of their region from the rest of Nigeria. In June, Kanu told DW that if his demands for a referendum on independence for Biafra weren't met, there would be no elections there.
Nigeria sent security forces to the region last month in a move generally seen as an attempt to clamp down on the tensions in the region (although it said the military's mission was to tackle rising crime).
In 1967, a unilateral declaration of Biafra independence led to a civil war which killed at least 1 million people. Most of them were Igbos who starved to death following a military blockade.
Kanu's disappearance and the security crackdown on his supporters have drawn comparisons to Boko Haram's founder, Muhammed Yusuf. He died while in police custody in 2009 during a military operation in Maiduguri in northeastern Nigeria.
Don Okereke, a security expert warned that history could repeat itself. "If anything happens to him (Kanu), the reactions are likely to be very violent in the southeast."