FOND DU LAC COUNTY, Wis. (CBS 58) -- The Fond du Lac County Sheriff's Office says potential evidence connected to a 1983 missing persons case was located during the execution of a search warrant Thursday, July 16, in the Village of Campbellsport. 

Detectives searched the home of Robert "Bobby Joe" Fritz, who was last seen on May 14,1983, at 5 years old.

The sheriff's office says due to the potential evidence located on Thursday, a larger excavation is now taking place in the basement of the home.

Sheriff's officials are working with agents from the Wisconsin Department of Justice Division of Criminal Investigation and the Crime Lab to process any additional evidence that may be found. 

Anyone with information is asked to contact Detective Tyler Tikkanen at 920-929-3384, or to remain anonymous, call the Fond du Lac County Tip Line at 920-906-4777.