Police said Rani, a divorcee living with two men, admitted that she along with one of her lovers had planned to kill the child. She was allegedly murdered on Tuesday night by one of the lovers and the body buried at Arakunnu by all the three.
Police suspect that the child may have been sexually exploited.
A crowd gathered at the place where the child was buried as police exhumed the body.
In another incident in neighbouring Kottayam district, a six-year old boy was injured when he was thrown off the first floor of the Kottayam Medical College Hospital by a man, stated to be mentally unstable.
The boy's mother had come for delivery at the hospital when the incident occurred. The child was out of danger, hospital sources said.