Japanese police are questioning the president of a company that manufactured anatomical skeletons after the discovery of the bones of an estimated 500 people in the garden of a suburban home in Tokyo.

The man, who has not been named as he has not yet been charged, is the head of a company called the Habara Skeletal Specimen Research Institute, the Mainichi newspaper reported, and has admitted disposing of the human remains in the garden of one of his employees.

The bones were discovered in November, after the death of the owner of the house in the Adachi district of Tokyo. The property was also used as offices for the company but authorities launched an investigation when a police officer sent to the house discovered what appeared to be human bones in the garden.

That suspicion was quickly confirmed and forensic officers eventually recovered the partial remains of around 500 individuals.

Police sources told the newspaper that a person questioned in connection with the inquiry said the company president had imported the bones from India “a few decades ago to use for skeleton models”.

Industry sources added that it was “common” for companies that produced anatomical human skeletons for Japanese schools, universities and laboratories to use real human bones up until the 1970s.