A high school teacher who admitted to sleeping with a student has been allowed to keep her job.

Janine Rayner's future at James Cook High School in Manurewa has been secured just a month after she confessed publicly to having sex with a Wesley College fifth-form boy when she was a teacher there two years earlier.

In a confidential deal, she can keep teaching if she meets conditions which include seeing a counsellor.

Board chairwoman Maureen Hilyard said the school had feared Ms Rayner would take a costly personal grievance case. "What was best for the school was basically the final issue."

The incident was never reported to teacher authorities, and the James Cook High board decided it could not investigate an incident that happened at another school.

The Teacher Registration Board, which has the power to deregister bad and incompetent teachers, has been left frustrated and annoyed by the outcome, particularly because another secret deal has been done.

Board director Dr John Langley said the board could not investigate the case of serious misconduct because the schools had not formally referred a case to it. "We have made that clear to both schools, and both of them have shied away from doing that. It is an issue that they are going to have to live with."

He was also incredulous that Ms Hilyard claimed the school failed to act because there had been no formal request from the Teacher Registration Board. "We do not have any legislative right to make a request of that nature."

Ms Hilyard said students and staff supported Ms Rayner and there had been no complaints from parents. "I would just like the school to be able to get on with what it does, and for the teacher to get on with her job. I think she has been through a lot."

Wesley board chairman Eric Beavis said his school made the right decision two years ago and there was no intention of revisiting it. "You need to remember that she was a relief teacher, she resigned straightaway, almost as soon as we heard of it, and was out of the school.

"It did not happen at the school, and it did not happen during school time. They were adults.

"I wish it would go away," he said. - NZPA