Port Clinton police dispatch said investigators searched an unoccupied house on East 5th Street, which is across the street from the Dilly home.
Police said a body was not found inside the house and Harley is still considered missing.
Harley was last seen leaving his house on the morning of Dec. 20. He did not make it to school that day.
Over the past few weeks, the FBI, Ohio Bureau of Criminal Investigation and the U.S. Marshals Service have aided the Port Clinton Police Department in the investigation. Volunteers also organized a search for the missing teen.
Dilly is 4 foot 9 and weighs 100 pounds. He has brown hair and green eyes. He was last seen wearing the maroon coat, gray sweatpants and black tennis shoes.
Anyone with information is urged to call the Port Clinton Police Department at 419-734-3121 or the National Center for Missing and Exploited Children at 800-843-5678. A reward is available.