An Irish police spokesman told AFP a child was removed from a house in Tallaght, just outside Dublin, yesterday under the provisions of the 1991 Child Care Act.
The child was transferred into the care of the health service. There have been no arrests in the case.
According to the Sunday World newspaper's online edition, police acted after receiving a tip-off that a girl was living there with a Roma family to whom she bore no physical resemblance.
The couple produced a birth certificate and a passport but the documents failed to satisfy police, it reported, adding that DNA tests may now be conducted.
Under Irish law, the girl can be kept in the care of the health service for one month before a final decision must be made to return her or seek a permanent care order.
The Health Service Executive refused to confirm the details, stating it does not comment on individual cases.
The discovery of the girl, known as Maria and dubbed the "blonde angel" by local media, has prompted thousands of calls from parents of missing children from around the world.
She was initially thought to be four years old, but later confirmed from dental checks to be five or six.
DNA tests revealed she was not related to the 39-year-old Roma man and his 40-year-old wife.
The couple, who are being held in pre-trial detention, deny the charge and claim that she was voluntarily handed over by her Bulgarian Roma mother who could not care for her.
