Two cardboard boxes containing human bones — apparently of a whole person — were left in front of a condominium in the town of Onjuku, Chiba Prefecture, on Tuesday morning, police said.

The 34-year-old manager of a real estate agency on the first floor of the building found the boxes outside the front of the agency when he arrived at about 8 a.m. and called the police.

According to investigators, the boxes, which were sealed with duct tape, each contained a translucent plastic box. One box contained a skull, while the rest of the bones were in the other box. Police believe the remains are the entire skeleton of one person. They have yet to determine the gender or age of the person, who seems to have died a considerable time ago.

Police said a nearby resident in his 60s claimed he found one of the boxes in shrubbery beside the condo and the other in a nearby parking lot, and carried them to the real estate agency.

The condominium is located in a residential area about 300 meters southeast of Onjuku Station on JR Sotobo Line.