A 1-year-old girl is back with her mother a year after the Mexico City doctors who delivered her allegedly sold her to another woman.

Authorities handed the baby to Vanessa Castillo on Thursday after tests proved she was the mother.

The case led to the arrest Wednesday of three doctors, a nurse and a receptionist at a hospital in a poor neighborhood.

According to Castillo, doctors refused to let her see the baby after the October 2008 birth, then first told her the infant was taken to another hospital and later that she had died and been cremated.

Castillo says she learned the truth in an e-mail thought sent by the hospital director's son.

Prosecutors are investigating whether other newborns were stolen at the hospital.