CEDAR RAPIDS, Iowa (AP) – A federal investigation is under way into the mishandling of Native American remains at Effigy Mounds National Monument in northeast Iowa.

The Gazette in Cedar Rapids says the National Park Service is looking into whether a crime was committed when a box of bone fragments was moved from a storage building to a former superintendent’s garage.

Jim Nepstad of the Park Service says the box was moved to Tom Munson’s garage without his knowledge when he retired from the Park Service in 1994. The box was inadvertently transported along with his personal possessions.

The Native American Graves Protection and Repatriation Act requires the return of human bones to lineal descendants or tribal organizations.

The monument features over 200 mounds created by prehistoric American Indians over 1,000 years ago.