Guinea Bissau’s junta had freed opposition leader Domingos Simões Pereira after a court ordered he should be allowed to travel to Portugal for medical treatment.
The former prime minister was arrested for a second time earlier this month charged with financing and providing logistical support for an alleged coup attempt in October.
Pereira was one of several senior politicians imprisoned by the military after it seized power in November 2025.
That coup saw the army replace President Umaro Sissoco Embalo just days after presidential and legislative elections.
It claimed it had acted to prevent bloodshed between supporters of rival candidates and announced it was taking control of the country for a period of one year.
Pereira’s release comes just days after the West African bloc ECOWAS urged the government to free all detained political figures, saying it would “bolster the credibility” of the country’s transition process.
The court will re-evaluate Pereira’s status after his 90-day medical leave expires.