In Osaka, Japan, Mayumi Saito, 53, entered a police station in November and confessed to having given birth to four children between 1992 and 1997, placing the infants in plastic buckets and pouring concrete over them.
She says she can no longer live with this on her conscience.
The case will be a difficult one for the police. They have to break the concrete in order to be able to determine the cause of the deaths.
For now, Saito has just been charged with the offence of transporting the dead body of the infants from one location to her new flat, which she moved into in mid-2015.