Hristos Salis, 39, and Eleftheria Dimopoulou, 40, were arrested and charged with abduction in Larissa, Greece Monday as police seek information that could lead to Maria's identity.
Maria has become the subject of international fascination after she was discovered during a gun and drug raid last week. Police became suspicious because the child, dubbed the "blonde angel" by Greek media, bore no resemblance to Salis and Dimopoulou.
DNA tests proved she was not related to the couple, while dental tests Monday revealed Maria is 5 or 6 years old, not 4, as was previously believed. Smile of the Child, the charity caring for the child said she was treated like a "dancing bear" by the Roma family, who forced her to perform and beg for money.
"It was an adoption that was not exactly legal, but took place with the mother's consent," Constantinos Katsavos, one of the lawyers for Salis, told reporters.
The charity said she was "filthy and terrified" when she was found.
"It was obvious that she was not a Roma girl," said Smile of the Child director Costas Yannopoulos. "The little girl was terrified when she first came to us and didn’t talk at all, but she is now calm and has been playing with other kids."
"She was living under bad conditions and was very dirty, but is now safe," Yannopoulos said.
But members of the Roma family denied she was being treated badly or that she was abducted from her biological family. They have claimed at points she was discovered as a baby abandoned, or that she was left with the camp by a Bulgarian woman.
"The family raised the child as if it was their own, although her father would come back every now and then to see her," said Babis Dimitriou, chairman of the Farsala village Roma Association. "The last time he visited was only five days ago, after the arrests had been made."
"All the other Roma here were telling the Bulgarian man to explain to the police that the girl was his, but he has now disappeared," Dimitriou said.
Yannopoulos said it was more likely Maria is Scandinavian.
Police said Dimopoulou claimed to have given birth to six children in less than 10 months, and had registered another eight children. On paper, it is a prolific progeny, but 10 children are unaccounted for. The family received more than £7,000n ($11,000) a month in benefits for children they claimed to have.
If convicted Salis and Dimopoulou could face 10 to 20 years in prison.