Police have decided to arrest a babysitter in connection with the death of a boy whose body was found Monday morning in an apartment building unit in Fujimi, Saitama Prefecture.

Another boy, apparently the other son, was found alive nearby.

The Kanagawa Prefectural Police said the apartment is the home of the babysitter, who was described as being in his 20s. The mother apparently hired the man, who was not identified, through an online babysitting broker website.

The babysitter was quoted by the police as telling investigators, “I drank medicine at noon Sunday and fell asleep, and when I woke up Monday morning, (he) was dead.”

The police began searching for the two boys after their mother, who is in her 20s, reported Sunday that her children were missing.

She told the police that she couldn’t get in contact with the babysitter at the time she was supposed to pick up her sons.

The police said the dead boy was aged about 2 and the other boy was about 8 months old. The cause of the older boy’s death was not reported.

Saitama firefighters said the younger boy was conscious and crying when he was rushed to a nearby hospital. His condition was not immediately available.

According to the police, investigators found the babysitter near the apartment building Monday, but he refused to speak with them, prompting them to enter his apartment.

The police said the mother found the man online and entrusted her children to him for three days starting Friday.

On Friday night, she left the children with a different man, whom she described as being in his 30s, even though he was not the babysitter she had hired. This man is believed to have handed over the children to the younger man.

The relationship between the man in his 30s and the younger man was not immediately known.

The apartment building is near Mizuhodai Station on the Tobu Tojo Line.

“I never knew there was a babysitting service operating in that apartment. I wondered what happened when I saw the ambulance,” a nearby resident said.