Experts have determined that the remains of about 60 people found at a construction site in central Germany date back far beyond World War II, police said Friday.

A city archivist suggested earlier this week that the bones, unearthed over recent days at a building site at the University of Kassel, could be those of slave laborers from a Nazi armaments factory.

However, after forensic experts took a closer look at dozens of the skeletons, police and city prosecutors said they now believe that the remains "date from a time significantly before World War II."

Experts found that none of the bodies examined showed signs of having been subjected to violence.

As a result, prosecutors plan to close an investigation of the case, the statement added.

In addition, an examination of about 40 sets of teeth showed that none of them had any traces of dental work. That, according to a forensic expert, suggested strongly that the bodies were buried well before the war.

Experts and investigators believe the evidence suggests that the bodies were buried following an earlier epidemic, police and prosecutors said.

Local media and historians have pointed to a typhus epidemic in 1814, and to the site's use in the past as a military hospital.

Authorities plan to recover all the remains from the construction site next week and then bury them, police and prosecutors said.