The baby girl, who was born in less than seven months, was found shattered in pieces near a drain at the flat by residents around 9am.
Forensic examination confirmed that the infant was born within the last 24 hours with the placenta still attached.
Wangsa Maju police chief ACP Muhammad Roy Suhaimi Sarif confirmed the incident.
He said the police have since detained a 36-year-old female suspect shortly after.
The woman was said to have been left by her husband two years ago and was since renting a unit at the flat together with her five-year-old daughter.
The case is being investigated under Section 302 of the Penal Code for murder.
