Ten more Europeans are still in custody in Chad where they are charged with attempting to take 103 African children out of the country.
French charity Zoe's Ark, which was behind the bid to fly the children to France, claimed that the children were orphans but this has been questioned by aid agencies, who say most of the children have families.
Six of those still being detained in Chad are employees of Zoe's Ark.
Before he flew back, Nicolas Sarkozy discussed the matter with his counterpart in Chad Idriss Deby and he urged Mr Deby to respect the right to presumption of innocence for those still being held.
Nicolas Sarkozy added that he had confidence in the justice system in Chad and he said that the two countries would work together to find a resolution to the case.
