The hospital operating the controversial baby hatch in Kumamoto Prefecture received a surprise last week when a boy 3 or 4 years old was reportedly put inside the day it opened, informed sources said Tuesday.

The hatch, Japan's first, was installed by Jikei Hospital to help save the lives of unwanted babies, which can be dropped off anonymously and put up for adoption.

According to the sources, the boy appears in good shape and can say that he was brought there by his father from Fukuoka Prefecture.

The private hospital refused to confirm that a boy was left in the baby hatch.