Professional cleaners who were hired to tidy up the home of a Japanese man stumbled across human remains which were later identified as his mother who had disappeared a decade ago.

The grisly discovery in Japan’s Kyoto prefecture has shocked and fascinated mainland social media.

The young man hired a cleaning company to tackle his four-bedroom, so-called garbage house, where he had lived with his parents and older sister, none of whom were interested in tidying up.

In Japan, the term “garbage house” was coined to describe particularly filthy dwelling places which emit a foul stench and can become breeding grounds for pests, hence the need for professional cleaning.

The man was left living alone in the house after his mother “disappeared” about 10 years ago. His father died a few years later, and his sister moved out for work.

As he prepared to relocate for a new job, the man hired the professional cleaning company which sent eight workers who planned to complete the job in seven hours.

However, three hours into the job, the workers made a startling discovery.

As they lifted old blankets and bedding, they saw what appeared to be human bones. Initially mistaking them for a model, they soon realised the grim reality and alerted the homeowner.

Suspecting the skeleton might be that of his mother, he immediately contacted the police, who confirmed that it was indeed hers.

The man said that his mother may have quietly passed away in her room, as she often left home for days without notice and rarely spoke to anyone.

“It’s possible that my mother came back after a few days away and no one in the family noticed,” he said.

Also, because the house was filled with stinking garbage, no one noticed any unusual odours.

The cause of her death and any potential legal repercussions for the family have not been disclosed.

The cleaning work was finally completed in February, costing 500,000 yen (US$3,400).

Kouki Nishioka, the owner of the cleaning company said: “Initially, the workers were shocked upon discovering the bones, but they managed to adapt more quickly than normal people.

“This is because we receive at least 10 orders a month to clean up after ‘lonely deaths’.”

The story left many online observers in China astounded.

“I remember people who push for marriage and having children often say if you don’t get married and have kids, no one will know if you die alone in your room.

“Well, this woman was married and had two kids, yet look what happened,” one person said.

“How can someone live in a house so filthy and smelly that they don’t even notice the smell of a decomposing body? Every time I read news like this, I’m stunned,” said another.

 - SCMP