A Bulgarian Roma couple are the biological parents of a four-year-old blonde girl found in a Roma camp in Greece last week.
DNA tests proved the couple were the parents of the girl, known as Maria.
Bulgarian prosecutors are investigating whether the mother, Sasha Ruseva, 35, agreed to sell her child in Greece, an accusation she denies.
Ms Ruseva said she left a seven-month old baby in Greece, where she worked as an olive-picker, in 2009 because she could not look after the child and needed to return to Bulgaria.
The girl was found last week hiding under a blanket at a Roma settlement in central Greece.
DNA tests showed the Roma couple she was with were not her real parents.
Maria is being looked after by a Greek charity.
Ms Ruseva and her 37-year-old husband, parents of nine other children aged between two and 20, live in extreme poverty in the town of Nikolaevo, around 280km east of Sofia.
"We all live in one room - my husband, I and all the kids," she told reporters yesterday.
"DNA analysis proved that Sasha Ruseva is the biological mother of the girl named Maria," Interior Ministry Chief Commissioner Svetlozar Lazarov said.
"It also showed Atanas Rusev as the biological father," he said.
There are an estimated 10 million Roma living across Europe, and they are one of its oldest minorities.
The Council of Europe, which monitors human rights, says they are also the most discriminated-against.
Speaking on RTÉ's Morning Ireland, the head of Human Trafficking and Child Exploitation at Interpol said the crime was a reality for all societies.
Michael Moran said cases brought before the courts in relation to child trafficking, such as organised begging gangs, organised marriages, and illegal adoptions, represented only the tip of the iceberg.
Asked about child-trafficking within the Roma community in Europe, Mr Moran said it was a problem the community itself had acknowledged and it was working with the authorities to tackle.
He said Interpol was about human rights-based policing and it did not target particular groups because of who they were.
Mr Moran said the migration habits of the Roma community made it susceptible to trafficking.
However, he stressed that "while it exists in the Roma community, it exists in other communities within our society".