A high school student had an abortion after falling pregnant to her physics teacher, a jury has been told.
Stephen Peter Morrow, 55, is on trial in the County Court charged with 11 counts of sexual penetration of a 16- or 17-year-old child under his care, supervision or authority.
He has pleaded not guilty to all counts.
Prosecutor Daryl Wraith said the girl was a student at a Melbourne school when the pair struck up a relationship in the 1990s.
He told the jury that Morrow used to pick up the girl after school and they would have sex in his car up to three times a week.
Wraith said that about four months into the relationship the girl discovered she was pregnant.
Morrow, who lives in Parkwood, Queensland, went to a fertility clinic with her, waited in the reception area and paid about $320 for the termination, Wraith said.
The relationship continued after the abortion, with the pair sometimes going to motels, the prosecutor said.
"This was a case of a young girl, it's submitted by the crown, who was vulnerable, who was seduced by a much older man," Wraith said.
"She's striving in a difficult year to succeed and he took advantage of her."
The girl called off the relationship about a month after she finished high school, the jury was told.
In 2003, she returned to the school to speak to Morrow.
She made a report to police and secretly taped a phone call with Morrow in 2006, by which time he had left the school and moved to Queensland, the court heard.
Wraith said that Morrow made clear admissions during the phone call.
He said that when the former student asked if their relationship was just about sex, Morrow replied: "No, of course not . . . It took too long for things to start."
The prosecutor also said that in that call, the former student told Morrow he was "the father of the child."
Wraith said Morrow did not fiercely deny the claim during the conversation.
Defence barrister Sharon Cure said the relationship between Morrow and the girl was later than the prosecution claimed.
"It started when they were student and teacher but it was not sexual during this period," Cure said.
She denied that the girl's pregnancy was the result of a sexual relationship with Morrow.
And, she said, the taped phone conversation was not an admission.
"This intelligent and manipulative girl speaks quickly and it's not clear what his response is," Cure said.
The trial before Judge Tom Wodak continues.