SACRAMENTO, California (AP) — The founder of an international music programme who was accused of giving semen-tainted flutes to California elementary school students was sentenced Wednesday to 18 years in state prison, the state attorney general’s office said.

John Zeretzke, 61, of Ventura was sentenced in Orange County Superior Court after pleading guilty to six counts of committing lewd acts against five girls under 14.

For more than 30 years Zeretzke was a teaching artist for the Music Center of Los Angeles, during which time he would share music lessons with students at Southern California schools.

In 2009 he founded Flutes Across the World, through which he contracted with schools to help children craft and decorate PVC pipe flutes. The non-profit also participated in mission trips to share music lessons in countries such as Haiti, Honduras and the Philippines.

Prosecutors alleged that in 2017, Zeretzke recorded himself ejaculating into flutes that were then distributed to five girls at Southern California elementary schools. He then is accused of taking photos of the girls using the flutes.

That year, California authorities began investigating reports of tainted flutes. Parents in some districts were urged to put the flutes in paper bags and turn them in to authorities for testing.

However, by the time the flutes were collected and tested, no traces of semen were found, prosecutors said at trial.

“There is no place in our society for crimes against children,” California Attorney General Xavier Becerra said. “We will not tolerate this kind of behaviour in our schools or anywhere in our state.”

Zeretzke still faces five federal charges that didn’t involve Southern California children. The East Bay Times has reported that he agreed to plead guilty to one federal count of producing child pornography, with the other charges to be dropped.

Zeretzke is scheduled to plead guilty in US District Court on October 20.