A teacher claims she was bullied and unfairly dismissed from a prestigious Hawkes Bay private school over alleged instructions to lie to parents about their children's achievement.

Former Hereworth School teacher Emma Fox filed an unjustifiable dismissal complaint against the Havelock North boys' school after a series of incidents in 2009 and 2010, an Employment Relations Tribunal hearing was told yesterday in Hastings District Court.

The school has denied all allegations and said Mrs Fox refused mediation attempts to resolve the issues.

Mrs Fox said the head of the junior school, Shirley Cameron, asked her to lie to parents about their children's achievement in mid-2009. Mrs Cameron has denied the allegation. The hearing continues today.