A retired investigator from a Florida sheriff's office said Wednesday that photos of boys tied up and gagged do not show a missing Iowa boy who disappeared 24 years ago while delivering newspapers.

Nelson Zalva, who is now working for the Hillsborough County state attorney's office, said he investigated the photos while he worked at the Hillsborough County sheriff's office in 1978 or 1979.

"I remember this case," he said. "I identified the kids portrayed in the photos. It was definitely investigated by me several years prior to the disappearance of Johnny Gosch."

The photos were in an envelope that was dropped off at the West Des Moines home of Johnny's mother, Noreen Gosch, on Aug. 27.

One photo is black and white and shows a boy bound and gagged on a bed. The other is a color photo that shows the same boy in a similar pose with two other, unidentified boys who also are bound and gagged.

Noreen Gosch turned the photos over to police who have been investigating the authenticity of the photos and to determine if they were of Gosch's son.

Lt. Jeff Miller, a West Des Moines police spokesman, said the department received an anonymous letter last week with a Tampa, Fla., postmark that said the photos were taken in the late 1970s and investigated by the Hillsborough County, Fla., sheriff's office.

Zalva said his investigation never resulted in an arrest because the children in the photos never admitted that the suspect touched them inappropriately.

"Basically, what happened is someone, maybe it was one of the parents, found the photos and called the sheriff's office and deputies went out there, impounded the photos and the case was assigned to me for investigation," Zalva said. "I worked a long time on it, getting the kids identified."

He said the boys in the photos had voluntarily posed for the photos, but he couldn't recall why.

"It was a case that bothered me. It was weird. What kind of pervert would do that?" Zalva said. "It's a sad situation."

He said the sheriff's office is now going through old microfilm in its archives to find the police report, which has the original photos attached.

Meanwhile, Miller said the investigation is continuing into who dropped the photos off at Noreen Gosch's house.

"If they are not of Johnny Gosch, someone is playing a horrible prank," he said.

Miller said Gosch has been informed of the photos' apparent origin and the Florida investigation.

A telephone message left Wednesday morning for Gosch was not immediately returned.