The group says it is "dedicated to orphaned children"
Six workers from French charity L'Arche de Zoe (Zoe's Ark) are facing charges of child abduction after attempting to fly 103 children out of Chad.
The group was formed by motoring enthusiasts from the French four-wheel-drive community to aid victims of the December 2004 Asian tsunami.
Its founder, Eric Breteau, is a volunteer firefighter and former president of the French 4x4 Federation.
Zoe's Ark says it is motivated by the firefighter's spirit and sense of duty, as well as the catchphrase "courage and devotion".
The group, which describes itself as a non-profit organisation "dedicated to orphaned children", is now focusing its activities on children caught in the four-and-a-half year war in Sudan's Darfur region.
In April, Zoe's Ark announced a campaign to evacuate 10,000 orphans from Darfur alongside other French charities including Sauver le Darfour (Save Darfur).
It said it wanted to place orphaned Darfuri children aged under five in foster care with French families, invoking its right to do so under international law.
Zoe's Ark founder Eric Breteau (left) is one of those held in Chad
But the charity has been accused of child trafficking in the case of the 103 children it attempted to fly out of Chad.
UN officials say many of the children are from Chad, not Sudan, and there is no evidence that they are orphans.
Zoe's Ark insists tribal leaders in Sudan told them all the children were Darfuri orphans. It says it wanted to save the children's lives and was carrying out a medical evacuation - not an adoption operation.
And it has proudly stated that its operations did not have official support.
On its website, the group says its plans will "surely expose [us] to the wrath of Khartoum, of certain politicians... who will cry scandal, speaking of ethics, illegality or the psychological traumas of uprooted children".
French Secretary of State for Foreign Affairs and Human Rights Rama Yade has accused the group of hiding its identity by registering in Chad under the name of Children Rescue. Mr Breteau heads both organisations.
Ms Yade says the government warned Zoe's Ark months ago that it risked breaking the law. She told Chadian officials of the group's plans back in July.
French police have been investigating the charity since then, and Mr Breteau was questioned by police in August about suspected plans to adopt children from Darfur.
Other aid and adoption groups have criticised the group's plans as "irresponsible" and amateurish.