Former Ivory Coast President Laurent Gbagbo will stay behind bars after prosecutors appealed against his acquittal on charges of crimes against humanity.
The International Criminal Court (ICC) in The Hague acquitted him on Tuesday and ordered his immediate release.
But on Wednesday prosecutors challenged the decision to release him, arguing that Mr Gbagbo might abscond.
They said he might not appear in court if his acquittal were to be overturned.
Mr Gbagbo had been charged with crimes against humanity in connection with violence following a disputed 2010 election that left 3,000 dead and 500,000 displaced.
He was captured in 2011 in a presidential palace bunker by UN and French-backed forces supporting his rival, Alassane Ouattara.
He is the first former head of state to go on trial at the ICC.