French police have released the chief of staff to Gabon's President Ali Bongo who was detained for questioning in a corruption probe after the Foreign Ministry said he had diplomatic immunity, a judicial source said on Tuesday.
Monday's arrest of one of Gabon's most influential and controversial figures, Maixent Accrombessi, had been sharply condemned by Libreville, stoking tensions between the oil-rich Central African country and France, from which it won independence in 1960.
France's Foreign Ministry received a letter from Gabon's presidency late on Monday saying that Accrombessi, who is one of Bongo's closest advisors, was on a "special mission" in the country from July 19 to August 5, the judicial source said.
The ministry informed investigators that the letter gave Accrombessi diplomatic immunity and police subsequently released him that evening, the source said, without giving further details.
The Foreign Ministry declined to comment. Gabon's government said Accrombessi was on an official mission to France, but declined to elaborate.
Gabon's former President Omar Bongo enjoyed excellent relations with France under a system known as "la Francafrique" whereby Paris granted political and military support to long-ruling African presidents in exchange for commercial favors.
But the friendship has cooled since his son Ali Bongo won a contested election in 2009 and because of an ongoing French-led investigation into Bongo family assets.
Accrombessi was being questioned over a contract for the purchase of military uniforms signed between Gabon and a French firm, French judicial sources said.
Accrombessi, who is a originally from Benin, is viewed with deep suspicion and animosity by Gabon's opposition. Critics accuse him of using voodoo against opponents and in April, a mob set fire to the Benin embassy to show their anger at the government over the death of a senior opposition leader.
French oil major Total is one of the biggest oil producers in Gabon, which pumps around 230,000 barrels per day.