Tokyo - Two neatly sealed boxes of human bones - one containing a skull - have been left on the doorstep of a real estate agent in Japan, police and reports said on Wednesday.

The 34-year-old manager of the firm in Chiba prefecture, east of Tokyo, found the two sealed boxes outside the door of his office on Tuesday morning, police said.

He called the emergency services after opening one of the boxes and discovering a human skull inside, a local police spokesman said.

The other box was found to contain a number of bones of varying lengths and sizes, believed to be from the same body.

“The remains appear to have belonged to one person, but neither the sex nor the age of the person is yet known,” the officer said, adding it was likely an adult and appeared to have been dead for some time.

Officers are investigating the incident in the town of Onjuku, and trying to establish where the bones came from. - AFP