Authorities in Chad have charged nine French nationals with abducting children and fraud.
Seven Spanish citizens, the crew of the charter plane used in the operation, are charged with being accessories to the crimes. Two Chadians are also charged.
The 16 Europeans were detained last Thursday as they tried to fly 103 African children out of Abeche in eastern Chad to live with families in Europe.
The accused include the president and other members of French organisation Zoe's Ark, which said it intended to help the children, not abduct them, and that it acted legally.
The children were due to be housed with host families who paid the group several thousand euro each.
Zoe's Ark said the operation offered a better life to orphans from Sudan's war-torn Darfur region, many of whose people have fled over the border to camps in Chad.
The charity says it was given statements from tribal leaders that the children were Darfur orphans with no known relatives, and that it was acting with the full knowledge of Chadian and French authorities.
The French government denies this, saying it warned Zoe's Ark months ago that it risked breaking the law.
Go behind the headlines with RTÉ's in-depth reporting about Chad's role in the Darfur crisis
