Niger’s new rulers want to charge ousted President, Mohamed Bazoum with high treason, a spokesman for the junta said on national radio.
The spokesman said Bazoum and his other “accomplices” would have to stand trial.
Bazoum was removed from office by a military junta in a coup on July 26.
On Sunday, the junta in Niger had still shown itself open to negotiations with the Economic Community of West African States, ECOWAS.
The group had demanded that the new rulers released the detained president a few days after the coup.
After the military seized power, it suspended the constitution and appointed their own transitional government.
President Bazoum had been held by the putschists ever since.
Niger, a country with around 26 million inhabitants and one of the poorest populations in the world, was until the coup, one of the last democratic partners of the United States and Europe in the Sahel region on the southern edge of the Sahara.
The coup had plunged the region into a political crisis.
At a special summit on Thursday in Nigeria, ECOWAS decided to activate a military standby force to restore constitutional order in Niger.
dpa/NAN
