Humanitarian workers have cast new doubt on a French charity's claims it was helping Darfur orphans by trying to fly them to Europe, saying that most of the children appear to have at least one parent.
The president of Chad, meanwhile, said some implicated in the case should go free.
Fallout from the scandal, meanwhile, reached across Africa to the Republic of Congo, where officials suspended international adoptions.
The charity, called Zoe's Ark, was stopped last week from flying the children from Chad to Europe, where the group said it intended to place them with host families.
Seventeen Europeans have been detained by Chadian authorities, including six French citizens who were charged with kidnapping. The group said its intentions were purely humanitarian and that it had conducted investigations over several weeks to determine the children it was taking were orphans.
Aid workers who interviewed the children at an orphanage in eastern Chad said most of them come from villages on the Chadian-Sudanese border region.
"Ninety-one of the children referred to a family environment made up of at least one adult person whom they consider as a parent," the UN's Children Fund, the UN refugee agency and the Red Cross said in a joint statement on Thursday.
The French foreign ministry and others have cast doubt on the claims by Zoe's Ark that the children were orphans from the war-torn region of Darfur, where more than 200,000 people have been killed since fighting erupted in early 2003.
The International Committee of the Red Cross and the two UN aid agencies said several days of talks with 21 girls and 81 boys aged between one and 10 "suggest that 85 of them come from villages in the border region between Chad and Sudan, in the area of Adre and Tine." Adre and Tine are both in Chad.
Thousands from Darfur have sought refuge in camps and villages in eastern Chad, so the nationalities of the children were still in question.
The children interviewed said "that they were living in Chadian villages for years, so they may turn out to be Chadian citizens, but until we go to their villages, we can't be sure," said Annette Rehrl, of the UN refugee agency.
Chadian President Idriss Deby, meanwhile, said on state television that journalists and the flight crew should be freed after a judicial process.
"I hope that that Chadian justice can very quickly shed light on this affair and that the journalists and the air hostesses, and those not involved, can be freed without delay," Deby said.
Three of the nine French who are detained are journalists, and seven Spaniards are known to be part of the flight crew. A Belgian pilot is also being held.