Updated

Greek police said Friday they have arrested a childless couple in Athens on suspicion of buying an 8-month-old Roma girl and trying to register her as their own, amid an international search for the parents of another little girl known as Maria who was found living with unrelated Gypsies in Greece.

Bulgarian authorities are now trying to establish whether a local Roma woman is the mother of Maria, a strikingly fair girl aged 5 or 6. The woman has been tested for a DNA match and served with preliminary charges of child selling, but has not been detained.

The case of Maria has drawn global attention, playing on the shocking possibility of children being stolen from their parents and sold. But its handling by media and authorities raised has concerns of racism toward the European Union's estimated 6 million Gypsies -- a minority long marginalized in most of the continent.

The couple arrested in Athens on Wednesday allegedly paid a Roma woman 4,000 euros ($5,500) for the baby, a Greek police statement said. Authorities are looking for the baby's birth parents and potential intermediaries in the alleged transaction.

The suspects, aged 53 and 48, were expected to be charged later Friday with child abduction, which under Greek law can include cases where a minor is voluntarily given away by its parents outside the legal adoption process.

The same charges were brought against the couple with whom Maria was found living in a Roma settlement outside Farsala, in central Greece, a week ago. They have been jailed pending trial, are also suspected of fraudulently obtaining birth certificates for a total 14 children.

Greek authorities are trying to work out whether the children all exist, or whether the alleged document fraud was part of a welfare scam -- the couple allegedly received more than 2,500 euros a month in family benefits.

They insist they were looking after Maria with their own five children after an informally arranged adoption.

The girl was placed into the care of a children's charity and her DNA details were provided to Interpol which has so far failed to match her to any missing children declared in its records, from Poland to the U.S.

On Wednesday, another Roma couple was charged with child abduction on the eastern Greek island of Lesvos, after police found them with a baby boy that was not their own. The couple allegedly told authorities that they were childless and had been given the baby by a Roma woman in Athens who had five children of her own and took pity on them.