Japanese police data for the first half of this year has revealed that the bodies of nearly 4,000 people who died alone at home in the country were not discovered for more than a month after their deaths.

The National Police Agency released a report it hopes will help shed more light on the social problem of people who die unattended at home after leading a lonely or isolated life.

The report includes 102,965 individuals on whose bodies police conducted autopsies or other investigations between January and June.

It shows that about 30 percent of them, or 37,227 people, were found dead at home after living alone. Persons aged 65 or older accounted for over 70 percent of that total. The largest group was people 85 years old and above, at 7,498, followed by those aged 75 through 79 at 5,920 and those aged 70 through 74 at 5,635.

About 40 percent, or 14,775 people who died alone at home were found within one day of death. But 3,936 were not discovered until more than 30 days after their deaths, including 130 who were found after at least a year had passed.

The police agency plans to provide the report to a Cabinet Office working group studying how to address the issue of unattended deaths.