Prosecutors in the Central African Republic have accused a French national of espionage, conspiracy and harming state security.
The man, Juan Remy Quignolot, was arrested last month in the capital Bangui.
Photos on social media show him outside a police station in front of an assortment of weapons and ammunition said to have been found in his home.
France has criticised the arrest, and said the pictures had been manipulated.
The announcement comes a day after France suspended aid and military co-operation to the Central African government for failing to stop what it called disinformation campaigns against France.
