An email from the superintendent of the Fountain Valley School District was sent to families on Thursday, notifying parents of the investigation.
In the letter, it said an independent contractor, who has not been identified, provided a music program for fifth grade classes at Courreges Elementary School in June. The suspect gave students flutes and recorders that may have been contaminated.
"I think there's something really sick going on here," said one woman from Fountain Valley.
The superintendent asked that any parents who had children in the Flutes Across the World program remove the instruments from their child's possession and place it in a paper bag. All flutes will be part of the investigation.
The U.S. Postal Inspection Service is also part of the investigation and said in part in a statement that "protecting children from crimes of sexual abuse and exploitation is a priority."
The Capistrano Unified School District also sent parents a letter about the contractor and requested any of those flutes in a child's possession be confiscated and submitted to the investigation. CUSD is trying to figure out how many schools are affected there.
A parent at Newport Mesa Unified School District said four classrooms at Sonora Elementary School are also impacted.
"Just plain wrong to put any kind of fluids just give it to the kids especially if they trust the teacher," said Morris Nguyen, of Huntington Beach.
So far, one school in the Newport-Mesa Unified School District is involved in the investigation as well as one school in the Fountain Valley School District. It was unclear how many schools were involved in the Capistrano Unified School District.
The investigation was ongoing.