Teachers have accepted gifts of underwear, and invitations to students' birthday parties - and later claimed to be unaware such actions were inappropriate.
Now some in the profession are calling for the education minister to step in and provide better training on professional boundaries, after a rise in the number and seriousness of offences committed against students.
Patrick Walsh, a long-standing member of the Teachers Council's disciplinary tribunal, said it was clear after six years on the tribunal and speaking with principals and teachers nationwide, that the quality of training around professional boundaries and student safety was at times non-existent.
Some teachers were so concerned with thinking they needed to be friends with students that they accepted inappropriate gifts and invitations because they were flattered, he said.
Texting and social media, including Facebook, had also contributed to the blurring of lines on what was acceptable between teachers and students.
The disestablishment of the Teachers Council and transition to the new Education Council of Aotearoa New Zealand (Educanz) was a "window of opportunity" for Education Minister Hekia Parata to ask the new council to offer better training.
New primary school teacher Penny Brown said there were concerns within the profession over what some teachers might think was appropriate.
"People have different thresholds of what is acceptable."
She said ethics was taught at teachers' college, but better guidelines around correct protocol, especially to do with social media, would be helpful.
At the end of a teacher placement, Miss Brown said she had become uncomfortable when she was asked by the classroom teacher to provide the children with her email address so they could stay in contact.
"It was my personal email address and I wasn't comfortable, but I did it because I was asked, and then I started to get harassed by some of the kids.
"I felt like that was crossing a boundary, so made sure the contact fizzled out quickly."
Post-Primary Teachers' Association president Angela Roberts said there were already many steps in place to ensure teachers were of a high standard, but any case involving an inappropriate teacher-student relationship was serious. She said there would need to be proper checks and audits to make sure any additional training was delivered effectively.
Parata said schools were required to have clear policies around boundaries and appropriate use of technology when teachers were dealing with students. It was intended Educanz would approve initial teacher education programmes and consider changes and improvements, she said.
Incidents of inappropriate relationships heard by the Teachers Council's disciplinary tribunal:
August 2013: A relief teacher asked a mother's permission to befriend her year 8 child on Facebook, which the mother approved. The teacher was given the pupil's cellphone number and texted it 165 times in a month. Texts had frequent references to being in bed.
December 2012: A teacher discussed his personal relationships with a student, looked up personal details on a school database, then visited her at home and tried to talk her into going out with him.
July 2012: A teacher paid another teacher $300 for pot while at school. When drinking with staff and ex-students, he told a former deputy head girl he wanted sex with her.
- The Dominion Post