Parents were warned Saturday that a music teacher with a nonprofit group may have handed out flutes to schoolchildren that were tainted with his own semen.
A state and federal investigation was under way into whether youngsters at schools around Southern California may have received tainted flutes.
The Los Angeles Unified School District said it was cooperating in an investigation of alleged "inappropriate sexual conduct involving a musical performer" that affected at least 13 school districts.
One LAUSD school may have been involved, the district said in a statement.
Several other Southern California districts notified parents by email on Friday and Saturday that a performer associated with the nonprofit group Flutes Across the World was being investigated.
"The performer distributes a flute-like musical instrument made of PVC pipe or bamboo to students during a music lesson, and the allegation is that he contaminated some of these instruments with semen," Joan Lucid, superintendent of the Saugus Union School District, notified parents on Saturday, the Orange County Register reported.
The performer was not immediately identified.
Messages seeking comment from John Zeretzke, founder of Flutes Across the World, were not immediately returned Saturday night.
Parents in some districts were urged to put the flutes in paper bags and turn them in to authorities for testing.
KNBC-TV reported that a parent identified only as Nate went to the police station in Fountain Valley on Friday night to turn in a flute given to his child, who attends Courreges Elementary School.
"It's disgusting, it's unreal, you can't even really fathom it," another parent, who wished to not be named, told the station. "It made me sick to my stomach."
Flutes Across the World has provided musical presentations at several local school districts. The Fullerton School District said fourth- through sixth-graders at two schools had the program in the 2016-2017 school year.
Presenters at such programs "are never alone with children" but the performer won't return to the district out of "an abundance of caution," the district said on its website.
The district said the music program was sponsored by the Philharmonic Society of Orange County.
The society sponsored Flutes Across the World to bring the program to six classrooms in three years, spokesman Chantel Uchida told the Register.
"We're so shocked and disgusted," Uchida said of the allegations. "We will be stepping back from this. There are no plans to continue it in the future."
