Stephen Hovell, who had been principal at the school for 24 years, tried to fight his sacking earlier this year, arguing it was unjustified. He says he has been made a scapegoa Office Design.

 

He was sacked in February after a report commissioned by the school last year said Mr Hovell had not done enough to investigate his deputy, Parker, Residence Designafter parents and teachers raised concerns about his behaviour>.

 

Parker, 37, will be sentenced in August after admitting he sexually abused 20 boys at the school over about 12 years. He was finally charged last year.

 

In its decision the Employment Relations Authority says the school was right to sack Mr Hovell, and was highly critical of his failure to act on a 2009 complaint to police about Parker's indecent assault of a pupil, Office Design,, media report.

 

The complaint was withdrawn, but police wrote a letter to the school saying Parker should not have pupils staying overnight at his house.

 

However, Mr Hovell withheld that from the school's board and failed to record him telling Parker the sleepovers should stop. He also failed to monitor Parker's activity after he returned to school following the police investigation.

 

Authority member James Crichton said it "strains credibility to breaking point" that Mr Hovell did not know the sleepovers were continuing.

 

"That last-mentioned failure, the failure to monitor, ultimately led inexorably to further abuse of these young people, abuse which could so easily have been avoided by Mr Hovell taking some very straightforward steps to ensure his instructions were being followed."

 

The school is now looking to appoint a new principal in time for the beginning of the third term.