Gabon's Constitutional Court began hearing arguments on Thursday in advance of its ruling on an election that opposition leader Jean Ping said was rigged to give President Ali Bongo victory.
The court's nine judges are expected to rule by Friday on Ping's complaint and could announce a recount or final results.
The election has drawn unwelcome scrutiny on Bongo, whose family has ruled the oil-producing country for almost half a century. France has called for a recount and the European Union questioned the integrity of the results.
Six lawyers for Bongo and two for Ping sat at tables about five metres apart in the glass-domed courtroom. All wore black robes and white cravat-style collars. At least 12 armed security personnel stood guard outside the courthouse.
The top document on a pile stacked on the opposition's legal table was titled Province Haut-Ogooue, a stronghold region for Bongo who won 95 percent of the vote there on a 99.9 percent turnout, according to electoral commission results.
Ping says that region's result was rigged, which explains the president's victory by less than 6,000 votes. At least six people died in clashes after the result of the Aug. 27 election was announced.
Bongo became president in 2009 on the death of his father, who ruled for 42 years. Ping says he has no faith in the court because of its ties to the president.