Entrance to the building in La Courneuve, Paris, where the family was discovered.

Entrance to the building in La Courneuve, Paris, where the family was discovered. Photo: AFP

French officials are investigating a couple of Indian origin after finding three young boys confined in appalling conditions in a suburban Paris flat.

The parents were taken in for questioning after the 27-year-old mother gave birth in January and staff at the hospital alerted social services when they were struck by her indifferent attitude to her baby girl.

Subsequent investigations showed there were three boys - aged between two and six - confined in the couple's flat in the gritty suburb of La Courneuve.

The boys had severe developmental deficiencies and could barely walk or talk.

"These were children living wild and basically left to fend for themselves," a source close to the case said.

Neighbours in the high-rise estate, which housed about 4000 people, said they were not aware of the children's existence.

"At times I saw the father... but I never saw the children," said a neighbour who lived across the landing.

"Sometimes I heard a bit of noise and some crying but that's all," he said.

Sources close to the case said the children did not appear to have suffered beatings or sexual abuse but were confined to a room in the flat that only had mattresses.

"It wasn't very clean or tidy but it wasn't a dump either," a source said. The children had not been vaccinated and appeared never to have been taken to a doctor.

The family had been living in the complex for six years.

The father, 33, and the mother were in custody and being investigated for depriving the children of care. They could be jailed for seven years and fined €100,000 ($A153,000).

Neither parent worked but they took child benefits.

The father told officials he intended to take the boys to school "when they learn how to walk". The mother spoke very little French.

AFP