Wesley Ellis, 37, had pleaded guilty to sexual penetration of a 16-year-old child under his care after having sex with the teenage girl on 12 occasions in 2015.

County Court Chief Judge Peter Kidd on Tuesday jailed Ellis for a minimum one year and 10 months, saying the sentence needed to be significant enough to deter others, particularly teachers, from engaging in such crimes.

“As the victim’s teacher you occupied a significant position of authority and trust in the community with respect to your students,” Chief Judge Kidd said. “The community is entitled to have confidence in the very significant trust placed in our teachers with our children.”

The student helped care for her father, who suffers a terminal illness, and relied on her teacher, confiding in him about her family, the court heard.

Ellis had given her his mobile phone number, telling her she could call him 24 hours a day, and they began text messaging each other. They began an emotional relationship, and later had sex in hotels or his car on 12 occasions last year.

He had picked up the teenager in his car, waited for her to change out of her school uniform and took her to high-end hotels or restaurants.

Ellis booked hotel rooms and drove the girl to secluded car parks near Melbourne Airport so they could have sex, which is where they were caught by Australian Federal Police officers in November.

Both had lied to police about the girl’s age and how they knew each other, the court heard.

Defence barrister Ian Hill, QC, previously told the court Ellis had been going through marital problems when he offended, and thought he was in love with her.

The teacher had a “deluded fantasy” that he could maintain the relationship with the student, Mr Hill said.

While the judge accepted that Ellis had not set out to pursue the student in a predatory way and that the crime did not involve sexual deviance, he said his offending involved a high degree of planning: “You allowed your needs to override your obligations to your adolescent student.”

Ellis had also repeatedly chosen to have sex with the girl, despite having had “ample opportunity” to stop, he said.

Judge Kidd said he had given Ellis a shorter non-parole period because of his positive prospects for rehabilitation and his personal circumstances. He also gave him a shorter sentence because he had pleaded guilty to the crime.

“The community requires less in the way of protection by way of a lengthy period of incarceration without the possibility of parole,” the judge said. Ellis’ wife gave a character reference to the court, saying he was a good man, and described his offending as “out of character”.