Baby born to sister and brother may be taken into care

French authorities have begun an investigation into the parental fitness of a 62-year-old woman who gave birth to her brother's baby after a £56,000 operation in the United States.

The investigation, by a children's judge, could, in theory, lead to the baby – and a second baby, produced with the brother's sperm – being taken into public care. French authorities would, however, have to be satisfied that the two children – biologically full siblings – are in physical or moral danger if they remain in the "parental" home.

There is a history of violence within the family. The sister and brother parental team live with their 80-year-old mother in a crumbling mansion in Draguignan, in the south of France.

The matriarch, Marie, has told the French media that her son and daughter created the babies so the family fortune could be passed down to her grandchildren and not dispersed to distant relatives. But the new mother, Jeanine Salomone, has disputed this, and said that she had always wanted to be a mother and preserve her family's genes.

The French Health Minister, Bernard Kouchner, said yesterday that the case was "at the frontiers of psychopathology and science fiction". But he pointed out that although post- menopausal pregnancies were illegal in France, the 62-year-old former teacher had received her treatment in California. "My first concern, and great anxiety, is for the children and their relations with the three people involved," said Mr Kouchner, himself a doctor.

Jeanine gave birth in Fréjus last month to a baby boy called Benoît-David. She told a French newspaper this week that she had received fertility treatment, and a donor egg, in Los Angeles and that the sperm had been provided by her 52-year-old brother, Robert.

Robert is physically disfigured and almost blind after a failed suicide attempt, alleged by neighbours to have occurred after a brother-sister quarrel about inheritance. It was also revealed this week that Robert was the biological father of a second baby, Marie-Cécile, carried to term by an American called Deborah – who also provided the donor egg for Jeanine's baby.

Marie-Cécile and Benoît-David, born 6,000 miles and a week apart, now live in the family mansion in Draguignan, are therefore full biological sister and brother.

The public prosecutor for the Draguignan area has described the case as "incest, but social incest not biological incest". Despite a preliminary inquiry, it appears that the family – who are said to have a fortune of around £9m – have not broken the French law.