NEW YORK (AP) - An elite New York City prep school has apologised for sexual abuse perpetrated by teachers and administrators over a three-decade span.

The apology was made in a letter posted on The Horace Mann School's website on Friday.

Board Chairman Steven Friedman and Head of School Thomas Kelly wrote that the "unconscionable betrayals of trust never should have happened."

The letter also said the school's board would eliminate a board position of trustee emeritus and create an advisory board on student safety.

They said a private mediation report produced 31 impact statements by abused students and that settlements had been reached "with the great majority" of those cases.

In April the Bronx district attorney's office said the statute of limitations to prosecute suspected sexual abuse had expired.

In the letter Friday, Mr Friedman and Mr Kelly said the school had hired a private mediation firm which presented the board of trustees with impact statements from 31 individuals who described their abuse. They said settlements have been reached with "the

great majority" of those individuals.

Additionally, Mr Friedman and Mr Kelly said the school's board would eliminate a board position of trustee emeritus and create an advisory board on student safety, which may include a victim of sexual abuse.