Brazilian President Luiz Inacio Lula da Silva has criticised a Catholic archbishop for ex-communicating the mother of a nine-year-old who had an abortion after her stepfather raped her.

Gomes Sobrinho, the archbishop of Olinda and Recife, has also ex-communicated the doctors who performed the abortion on the girl, who was 15 weeks pregnant with twins.

"As a Christian and a Catholic, I deeply regret that a bishop has had such conservative behaviour," Lula said.

He praised the doctors in the northeastern Brazilian city of Recife for their decision to perform the abortion. "In this case, medicine is more right than the church," Lula said.

Doctors had said that the girl, who weighed just 36 kg, was not capable of continuing the pregnancy and her life was in danger.

The abortion was induced with medicines Wednesday and the girl, whose identity was not made public, had recovered and was released from hospital.

The stepfather, 23, who admitted the abuse, was arrested last week. He was accused of raping the girl and her 14-year-old sister on a number of occasions. According to police, the girl had been sexually abused since she was six.

According to the president, conditions of poverty can often destroy the family structure and lead to this kind of violence.

"If father and mother aren't doing well, there's no doubt the kids aren't either. Parents have to give an example," said Lula, who has also grown up in poverty.