Chinnaponnu, who already has a five-year old son, gave birth to the girl baby at the Primary Health Centre at Indoor in the district and returned home yesterday with the healthy baby, police said.
However, the parents brought the baby to the Government Medical College Hospital today with the complaint that it was unwell.
Doctors after examination said the baby was already dead.
Suspecting it to be a case of female infanticide, doctors informed police, who are investigating.