The body of a 7-year-old girl who vanished Saturday was found Monday morning in a river in the village of Otari, Nagano Prefecture, the police said.
They identified the body as that of Rina Machida, who had been staying at her grandparents' home in the village. She had been reported missing after leaving the house before noon Saturday.
Investigative sources were looking into the possibility that the girl had accidentally fallen into the river.
The police said no injuries were found on her body and that there had been no reports of suspicious persons in the area around the time she went missing.
The village is surrounded by a river, forests and mountains.
Earlier, the girl's sandals were found in bushes about 300 meters from the house, but a police dog used in the hunt failed to turn up any trace of her whereabouts.
She was wearing a pink T-shirt and gray short pants.
On Monday, about 150 police officers, firefighters and local residents gathered to comb the area for the girl, searching vacant houses, warehouses and the surrounding mountains.
The police initially said they had suspected she might have lost her way in the mountains.
The girl vanished at around 11:40 a.m. after telling her grandmother that she would follow her mother, who had left minutes earlier with her brother for a community center about 50 meters away. She had been staying at her grandparents' home with her family members for the summer holidays.
A resident of the village reportedly saw Machida around noon Saturday in front of a shrine near the community center.
Her mother called police at around 1:35 p.m. Saturday, saying the girl couldn't be found anywhere.