Police raided a home in Sydney's southwest at 6am on Thursday and seized electronic devices that allegedly contained a significant amount of child abuse material.
Officers allegedly found online chats between high school teacher Nathaniel Ballesta and a teenage girl spanning from 2021 to 2025.
The discussions revealed he had been trying to groom the child and procure her for sex, police allege.
The girl, a former student of the 35-year-old, cannot be identified as she was a minor at the time.
"A number of measures have been put in place to safeguard her," Detective Acting Superintendent Adam Powderly said on Friday.
"It's very confronting and very concerning when I see trusted members of our community like educators allegedly involved in offences like this."
He said not all of the information police gathered related to one victim, suggesting more victims could be uncovered.
Ballesta had been stood down and was unable work in any NSW public school, a state education department spokesperson said.
He came to the attention of the sex crimes squad when he allegedly uploaded child abuse material to a cloud-based service on May 19, police said.
Cloud-based platforms such as Google Drive or Microsoft OneNote share data between computers over the internet rather than storing it on hard drives.
Ballesta was arrested as part of an ongoing investigation into sexual abuse and exploitation of children facilitated by the internet and communications devices.
He was charged with a slew of offences, including three counts of possessing child abuse material and three counts of causing a child 14 and older to make child abuse material.
Also among the 10 charges are two counts of using a carriage service to procure a child under 16 for sexual activity and using a carriage service to engage in sexual activity with a child.
Ballesta did not apply for bail when he appeared at Campbelltown Local Court on Friday.
His matter will return to court in July.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
Lifeline 13 11 14
Kids Helpline 1800 55 1800 (for people aged 5 to 25)
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