Gbagbo’s lawyers on May 1 filed a request for the “interim release” of the 67-year-old former president, who was transferred to the Hague-based court in November 2011.
They argued he should be released pending his trial because he is in poor health and would only be able to properly prepare for his defence outside of prison.
Gbagbo faces four counts of crimes against humanity – murder, persecution, rape and other sexual violence, and other inhumane acts – stemming from election violence after he lost the Ivory Coast’s presidential poll in November 2010.
In a ruling released Thursday by the ICC, Judge Silvia Fernandez de Gurmendi said: “The gravity of the charges against Mr Gbagbo, and the lengthy prison sentence that may ensue in the event of conviction, constitute an incentive for him to abscond.”
She added that Gbagbo “appeared to have the political motivations as well as the necessary political contacts and funds to abscond.”
Gbagbo refused to step down in favour of his long-time rival Alassane Ouattara, who was declared the winner and is now president.
About 3,000 people died in the ensuing five months of unrest before Gbagbo was arrested in April 2011 by forces loyal to Ouattara, with UN and French military backing.
Prosecutors say Gbagbo continues to claim the presidency and would want to return to power if released, the judge said.
He is due in court August 13 for a charge-confirmation hearing.