A teacher at the centre of an investigation by the Education Council left his school last term and has not been in contact with students since.
The man was a teacher at Rathkeale College, an Anglican boys secondary school on the outskirts of Masterton in the Wairarapa.
The allegations being investigated, which have aroused "community speculation", also involve St Matthew's Collegiate, a high school for girls in Masterton.
However, the schools are staying silent over the allegations despite increasing speculation over the matter.
An email sent to Rathkeale parents by principal Willy Kersten and Board of Trustees chairman George Murdoch said they had been advised not to elaborate "in relation to recent conjecture that has become public".