It was gathered that the 28-year-old suspect, identified as Arabe Basi, conspired with a woman called Iya Mana, who injected her, after which, she was delivered of her baby.
She was said to have immediately thrown the baby into a septic tank.
The incident occurred on Saturday, July 28, No 12, Edidi Street, Amukoko area of Ajegunle.
The suspect allegedly ran away, but the police later rearrested her from her hideout.
According to an eyewitness, Miss Adebanwo Adeola, they were in their house at about 6:00a.m. when the woman came to their area as if she wanted to fetch water from the septic tank.
She said: "Suddenly, the woman brought something that looked like a baby wrapped in a white cloth and threw into the well. Immediately after she did that, she ran away.
"The woman is a heartless mother. How can a mother who carried the pregnancy of her baby for months decide to take the life of the baby in that manner? God will not forgive her. I don't know what she might have been going through, this is sad.”
Confirming the incident, the Lagos State Police Public Relations Officer (PPRO), CSP Chike Oti, said the woman was arrested from her hideout after the incident was reported at Amukoko Police Station.
Oti said: “On July 30, at about 11:00a.m. a woman came to the Amukoko Police Station to report that on July 28, at 5:15a.m., one Arabe Basi who was seven months pregnant conspired with one woman called Iya Mana and injected the suspect as a result, she delivered the baby prematurely and threw the new born into a septic tank.”