A female teacher has been deregistered after she had a sexual relationship with a 16-year-old boy in her English class at Hastings Boys' High School.
The woman owned up to the relationship after principal Rob Sturch was shown screenshots of text messages between her and the boy last June.
She was stood down immediately and later resigned.
Sturch has previously said she was a respected teacher who had made a fundamental error in judgment.
"This will have tragic consequences on her future and the school is in shock," he said.
The Teachers Disciplinary Tribunal, in a decision issued today, has suppressed the teacher's name "given the strength of the evidence filed in support outlining the respondent's vulnerability to being identified".
The boy's name was also suppressed.
"Teacher E was Student A's English teacher," the tribunal said.
"On June 23, 2017, the school's principal received screenshots of text messages sent between Teacher E and Student A, which he considered to be suggestive of a sexual relationship.
"The principal met Teacher E the same day, showed her the texts, and outlined his concern that the respondent and Student A were in a sexual relationship.
"Teacher E admitted that she had been in a sexual relationship with Student A, that she was 'stupid', and that she 'had let everyone down'.
"Later the same day, the principal met with Student A, who confirmed that he and Teacher E had been in a sexual relationship.
"Teacher E was immediately stood down. A mandatory report was provided by the school to the Education Council on June 26, and the respondent undertook not to teach in the interim. She subsequently resigned.
"Teacher E was fully cooperative with the Complaints Investigations Committee's investigation. She candidly admitted the nature of her relationship with Student A and did not resist the conclusion that cancellation of her registration to teach is inevitable."
The tribunal concluded that the teacher had committed "serious misconduct", cancelled her teaching registration and ordered her to pay costs of $2226.11.
Sturch said last July that the boy's welfare was the school's paramount concern and he was given counselling.
"The student is still seeing the counsellor and there will be follow-up work with the counsellor and his family [in] term three," he said then.
He said he did not believe the relationship had been going on for long, possible a couple of months.
"I don't think it was a prolonged relationship - not a lot stays private within a school environment."
Police had not been involved because the boy was 16 and legally able to consent.