South-central Kansas investigators looking for a boy who disappeared nearly a decade ago searched a mobile home Wednesday where the child once lived with his adoptive family.

Authorities would not discuss what they were seeking or might have seized from the rural Sedgwick County home, nor its connection to the 1999 disappearance of 11-year-old Adam Herrman. The disappearance was never reported.

But Wichita media reported that the adoptive parents, Doug and Valerie Herrman, had moved the home to rural Sedgwick County from neighboring Butler County after Adam disappeared.

Investigators have also searched the Herrmans' current home in the Wichita suburb of Derby, as well as the empty lot south of the Butler County town of Towanda were the mobile home once stood. Authorities said the Towanda dig yielded one answer in the case, which they have not disclosed other than to say no human remains were found.

The Herrmans have said Adam ran away in 1999 but that they did not report him missing because they assumed he had connected with a sibling or gone back to his biological parents.

But relatives of the Herrmans have said the couple told them the boy was returned to the state Department of Social and Rehabilitation Services.

Adam Herrman would now be 21 years old. His disappearance only became public knowledge last week when authorities announced they had been searching for a boy who had been missing for nearly a decade.

Butler County Sheriff Craig Murphy has declined to say who provided the tip that began the investigation. But Wichita media reported Wednesday that Adam's sister and a cousin went to welfare officials in November inquiring about Adam.

The sister, Crystal Espinosa, declined to talk to an Associated Press reporter who went to her home Wednesday.

Linda Bush, a former sister-in-law of Valerie Herrman, said that Espinosa had cried about how her family treated Adam.

Murphy said the search will move Saturday to the Whitewater River and an adjacent wooded area just outside of Towanda. No specific tip led investigators to the river, he said.

"Kids have been known to go to rivers," Murphy said in a telephone interview. "And when you're talking about missing people, one thing you want to do is consider where people might dump stuff, so we're going to take a look.

"We're trying to do everything we can do. We might not find anything but at least we can say we looked."

Even as they search related areas, Murphy said his office also was trying to wade through a flood of e-mail and telephone tips that have come in since Monday, when he held a news conference announcing details about the case, including the boy's name.

"They're just coming in faster than I've got personnel to handle them," he said. "But (the publicity) has done exactly what we wanted it to do. People are being helpful, giving their thoughts, possible sightings."

Five of Butler County's eight detectives are actively working on the case, with some help from the county attorney's office, Sedgwick County and the state Department of Social and Rehabilitation Services, he said.

Tips are coming in from around the U.S., he said, and some include photos from the social networking sites MySpace and Facebook that the senders believe match a computer-enhanced photo showing what Adam might look like if he is alive.