Another infant has been left in the baby hatch for unwanted newborns at Jikei Hospital, the third placed there since the hatch opened May 10, sources said Sunday.
The third child, a boy several months old, was left in the hatch Friday, the sources said without revealing further details.
The news came only a day after word of the second child was reported.
Given that three children have been dropped off over a relatively short period, debate over the system will likely increase, with advocates calling it a "last resort" to save lives and opponents charging it gives the green light for parents to abandon their children.
The Catholic-run hospital has a policy of not disclosing or confirming each case. It plans to announce the number of cases once a year together with the Kumamoto Municipal Government, which has endorsed the system.
The sources said the hospital has confirmed the baby's health condition and reported the case to police and a local child consultation office.
The baby hatch received a boy aged 3 or 4 on its first day. A second boy about 2 months old was dropped off Tuesday with a letter saying his parents "just can't raise him," according to different sources.
The 2-month-old boy is in good health, the sources said.
The hospital set up the hatch, called "konotori no yurikago" (stork cradle), after studying a similar system in Germany. It is equipped with an incubator and designed to enable people to leave babies anonymously.
A note urges people to contact hospital staff if they change their minds.
Babies left there will be adopted or sent to homes for infants if the identity of the parents remains unknown or if the parents are deemed unable to raise them.