An investigating judge questioned the woman and her 48-year-old ex-partner and is to decide by Friday morning whether to file charges, the prosecutors office in the northern city of Ghent said.
The investigation "still has to determine whether the two children were given up in exchange for money," said prosecutors’ spokeswoman Annemie Serlippens.
The Ghent prosecutors office said it had opened an inquiry into the 31-year-old mother of five children, after it heard about her alleged activities on a television programme.
The show, Netwerk, revealed late last month the story of a boy dubbed Baby Jayden, who was allegedly sold to a childless Dutch couple by his Belgian parents via the Internet, creating a media storm.
In its latest show, Netwerk claims to have found a "surrogate mother" to whom the Dutch couple paid 350 euros (450 dollars) three times in the hope that she would have a baby for them.
After accepting the money, the woman told the couple that her "home-made" attempts at artificial insemination had not worked, Netwerk claimed.
The programme said she charged another Dutch couple around 2,000 euros for similar efforts but that after falling pregnant decided to give the baby "to a friend".
"There are suggestions of fraud, but we have to work out if everybody implicated in this report is telling the truth," Ghent prosecutors office spokeswoman Annemie Serlippens said.
She said the woman could face up to five years in jail if found guilty of fraud.
Paying a woman to act as a surrogate mother is illegal in the Netherlands but Belgium has no laws covering such actions, and this judicial void has encouraged women to offer their services over the Internet, Netwerk said.
(AFP/Expatica°