A California music teacher arrested for committing lewd acts against young girls allegedly recorded himself ejaculating into flutes then had at least five female students play the tainted instruments to fulfill his sick sexual fantasies.

The disturbing claims about John Edward Zeretzke, 60, of Ventura, were revealed in the recently obtained grand jury transcript from March, including his alleged confession to an online friend that his sexual fantasies were fulfilled by watching his pupils play his semen-tainted flutes.

Zeretzke founded music program of Flutes Around the World in 2009 and ran music classes in elementary schools in Costa Mesa and Castaic, California where students created pairs of decorated flutes, kept one, and donated the other to children in another country.

He was indicted in March for suspected lewd acts involving two Orange County girls and three girls in Los Angeles County - who were all under the age of 14.

California music teacher John Zeretzke, 60, filmed himself ejaculating into flutes and then photographed his students playing those tainted instruments to fulfill his sexual fantasies, according to a grand jury transcript of his case. Pictured above teaching in 2016

He was indicted in March for suspected lewd acts involving two Orange County girls and three girls in Los Angeles County - who were all under the age of 14. Pictured above teaching in 2014

An earlier indictment alleged Zeretzke coerced a girl to produce child pornography, attempted to entice another person to send him sexually explicit images, received child pornography over the internet, and traveled to the Philippines to engage in sex with minors, according to The Mercury News.

He pleaded not guilty to all state and federal charges.

'You have been warned that it is a salacious and disturbing matter. There are going to be graphic images including sexual content where the victims are children, elementary school little girls, and that it’s very disturbing,' Deputy Attorney General Amanda Casillas told Orange County jurors in March during her opening statement, according to the obtained grand jury transcript.

She claimed Zeretzke was either in a hotel room near schools or his residence when he filmed himself and took pictures of himself ejaculating into flutes.

Then he later allegedly photographed students using those same flutes during workshops.

By the time the flutes were collected and tested there was no evidence of semen.

He was accused of inappropriate touching students in class, rubbing one victim's shoulders in class, massaging her back and whispering in her ear that she was pretty.

Zeretzke founded music program of Flutes Around the World in 2009 and ran music classes in elementary schools in Costa Mesa and Castaic, California where he taught students how to use the flute

Zeretzke is also accused of engaging in 'constructive touching' with his students.

'It’s constructive when the perpetrator, without actually touching the victim, causes the victim to touch herself with an object regardless of whether or not the perpetrator is present,' Casillas said.

In one online chat with an individual he described that his sexual desires and fantasies were fulfilled by having his female students use the flutes he masturbated into, it is claimed. He allegedly exchanged photos of his victims using the flutes with this online individual.

Following an investigation in 2017 authorities began collecting the flutes from students after learning they may have been contaminated with semen.

He held workshops for fourth-graders at Castaic Elementary from the 2015-16, 2017-18 school years. He also taught at Sonora Elementary.

'Two years ago, law enforcement informed us of this shocking situation, and we were equally relieved when notified the suspected violator was arrested,' Steve Doyle, superintendent of the Castaic Union School District, said.

Zeretzke is scheduled to return to court for a pretrial conference on August 14.