An elderly woman living in a small house with her two brothers claim none of them realised their third brother had died in his room and rotted away to just bones by the time they noticed anything.

The horrifying discovery was made at the family’s house in Kasugai in the Japanese prefecture of Aichi where the woman lived with her two brothers, one of whom went missing in 2015 when he was 66 years old.

The younger siblings didn’t seem to think that their brother’s  – who was identified as Sumio Suenaga – disappearance was unusual, and didn’t report it to the authorities until a year later.

The case didn’t go any further until the 69-year-old woman called the police after discovering bones in her brother’s room while she was cleaning.

It was then that she thought the bones may belong to her older brother.

She told the police: “I found something that I think are human bones.”

Officers showed up at the house and confirmed that the bones did indeed belong to a person.

While the police were unable to establish the deceased’s age or gender, officers believe there is a high chance the remains belonged to Sumio.

It’s unclear how the two siblings managed to spend multiple years in the home with a decomposing body in a nearby room and not notice anything.

The investigation is currently ongoing. Local media also reported that the home was not like a conventional Japanese house, which makes the undiscovered body even more unusual.

This article originally appeared on Over60.