Ifeanyi Ejiofor, his lawyer, confirmed this to the media on Friday.
He said: “Nnamdi Kanu has left the prison. This was after we perfected his bail conditions.”
On Tuesday, Binta Nyako, justice of the federal high court, Abuja, granted Kanu bail on stringent terms.
Nyako had told him to present three sureties – one of whom must be a serving senator; the second, a Jewish leader, and the third, a highly respected Nigerian.
All the conditions were met on Friday.
In October 2015, a magistrate court in Abuja discharged and acquitted Kanu of all charges of terrorism brought against him by the federal government.
But the government through its agent – the Department of State Services (DSS) filed another suit against him at the federal high court, Abuja, while keeping him in detention.
Adeniyi Ademola, another justice of the federal high court, Abuja, also ordered the unconditional release of Kanu owing to the reluctance of the DSS to file a charge against him at the time, but he was not released.
Kanu is currently facing charges of treasonable felony.