A Kentucky State Police news release says an autopsy ruled that the cause of death was blunt force trauma and the investigation is continuing. Authorities identified the girl as Amy R. Dye.
Todd County investigators found her body before dawn Saturday along a road between Trenton and Guthrie. She had been reported missing late Friday.
According to the Kentucky New Era, the sheriff's department took a man and woman in separate patrol cars from the investigation scene to Trenton City Hall for questioning.
KSP spokesman Stu Recke said he did not know if they were family members or suspects.
Information from: Kentucky New Era, http://www.kentuckynewera.com