The Teaching Council has deregistered a primary school teacher who deliberately pursued and married a vulnerable former pupil 34 years younger than himself.
The council's disciplinary tribunal said the man's behaviour was at the most extreme end of serious misconduct.
Its finding said the man taught the girl in years 7 and 8 at primary school.
He continued to see her after she moved to secondary school in 2012 through visits to his classroom and visits to his home and other locations, often with a friend.
The visits to the teacher's class prompted the principal at the man's school to warn him in 2015 about maintaining professional boundaries with former students.
As a teen she left secondary school at the end of 2016, and married the teacher in early 2019.
The tribunal dismissed the man's evidence that their relationship became romantic only in January 2017, after she had left school.
It said the relationship did not have to be romantic for it to be inappropriate.
"Student C reconnected with the respondent due to the fact he had been her teacher. There was no other reason. From that point, despite being warned by his principal about professional boundaries, the respondent embarked on a deliberate and consistent pattern of behaviour in pursuit of a vulnerable young woman.
"His conduct was about taking small yet purposeful steps so as to not draw attention to himself, and also in our view not to alert Student C herself to his intentions," the tribunal's decision said.
"The casual, seemingly innocent texting during school hours was to ensure he was always front of mind for Student C. He asked everyday questions about how she was and what she was doing to elicit continuing dialogue. His conduct was calculated and intentional."
The tribunal also discounted evidence that the girl had pursued the man.
"We wish to caution the approach that it is ever acceptable to apportion the initiation of a relationship on a student. At all times, a teacher has a professional duty to remove themselves from a situation whereby a student may wish to form a relationship other than an appropriate student - teacher connection.
"Given the inherent power imbalance, the onus is always on the teacher as the professional to set and maintain the boundaries," the tribunal said.
The tribunal interviewed the woman for its investigation and said it was troubled by her evidence.
"The impression Student C left with the Tribunal was of a vulnerable young woman who was impressionable, easily led and not overly street-smart," it said.
We agree with the CAC [Complaints Assessment Committee] that Student C is totally dependent on the respondent, financially, socially, and emotionally. Her role in the relationship is about fulfilling his needs and wants. The power imbalance now that they are married is as significant as it has always been.
"We do not accept the submissions that the respondent takes steps to mitigate that. Quite the opposite. He has taken Student C away from her whānau and friends to the other side of the world. When they return to New Zealand, she sees her friends only in his presence in his home. His behaviour is about power and control not partnership and reciprocity."
The tribunal agreed to suppress the name of the teacher because it would identify the former student, now his wife. It also suppressed the name of the school.
It ordered the man to pay for half of the cost of the investigation and hearing.