In a statement Justice Minister Jeannot Ahoussou-Kouadio recalled how the former strongman had been arrested after fighting between government forces and pro-Gbagbo troops assisted by Liberian and Angolan mercenaries plus militias.
"Pending the opening of a judicial inquiry, Mr. Laurent Gbagbo and some of his companions have been placed under house arrest," he said.
Meanwhile, gunshots and pillaging marred the first day of Alassane Ouattarra's control of the country in the main city of Abidjan where residents fear more violence after strongman Laurent Gbagbo's spectacular collapse.
Already widespread in recent days, pillaging intensified in the city where a security vacuum left by the toppling of Gbagbo, whose refusal to accept his rival's election victory in November led to some four months of fighting that killed hundreds and displaced a million.
Responsibility for maintaining order has fallen on the Republican Forces that helped Ouattara claim his elected position. Police and military police, officially at the disposal of the new regime, have yet to fully resume their duties.
Tension in Abidjan has been further heightened by news that a former interior minister who was arrested along with Gbagbo, Desire Tagro, died on Tuesday in circumstances that remained unclear, sources said.
A Gbagbo supporter alleged Tagro was shot while in custody at the hotel where the ousted president was taken after his capture but one of the sources, a diplomat, said he might have tried to kill himself.