The judge will report to a district attorney who will decide if the 10 Americans are to be formally charged.
The missionaries were arrested on Friday and are accused of trying to take 33 children - whose ages ranged from two months to 12 years - into the neighbouring Dominican Republic without the correct documents.
The group, who are from a Southern Baptist church in the US state of Idaho, say they were only trying to save abandoned children.
But legal experts say taking children across the border without documents or government permission can be considered child trafficking.
The children were later taken to the SOS Children's Village orphanage, where those who were old enough and willing to talk reportedly said they had surviving parents.
Patricia Vargas, regional director of the orphanage, said: "Up until now we have not encountered any who say they are an orphan''.
"Up until now we have not encountered any who say they are an orphan''
SOS Children's Village
Vargas said most of the children are between three and six years old, and unable to provide phone numbers or any other details about their origins.
She said reports that the orphanage had turned some of the children over to their parents were untrue.
"The Americans apparently enlisted a clergyman who went knocking on doors asking people if they wanted to give away their children," Jeanne Bernard Pierre, the director of Haiti's social welfare agency, told the Associated Press news agency.
"One child said to me: 'When they came knocking on our door asking for children, my mom decided to give me away because we are six children and by giving me away she would have only five kids to care for,'" he said.
Max Bellerive, the Haitian prime minister, has suggested that Haiti was open to having the Americans tried in the US since most government buildings, including Haiti's courts, were crippled by a January 12 earthquake that destroyed much of the capital Port-au-Prince.
|Haiti was home to an estimated 380,000 orphans before the earthquake [AFP]
"It is clear now that they were trying to cross the border without papers. It is clear now that some of the children have live parents. And it is clear now that they knew what they were doing was wrong,'' Bellerive told the AP.
The prime minister said some parents may have knowingly given their kids to the Americans in hopes they would reach the US - not an uncommon wish for poor families in a country that already had an estimated 380,000 orphans before the earthquake.
Haiti's overwhelmed government has halted all adoptions unless they were in motion before the disaster amid fears that parentless or lost children are more vulnerable than ever to being seized and sold.
Bellerive's personal authorisation is now required for the departure of any child.
Investigators have been trying to determine how the American church group got the children, and whether any of the traffickers that have plagued the impoverished country were involved.