A newly released internal police report claims a senior detective in charge of child protection investigations did not initially report improper contact between a teacher at the school he helped govern and a student who later took her life.

Theo Ackroyd was a detective sergeant at Gisborne police at the time - and also the chairman of the board of trustees of the school where teacher Sam Back had taught Reiha McLelland.

He accepted he had a conflict of interest when police began investigating Back's intense relationship with Reiha, 13, before she took her life in August 2014.

But it