A former Wellington Girls' College teacher, who was sacked and then deported, has been ordered to pay the school $10,000 in legal costs after his claim of unjustifiable dismissal was thrown out.

In July, the Employment Relations Authority rejected a complaint from former economics teacher Dominic Speed, 41, that his sacking in December 2010 was unfair.

Speed, a British immigrant, had been the subject of separate investigations by the school and the Teachers Council at the time, prompted by domestic violence charges that he was facing. He was later acquitted.

During the school's investigation, it discovered that Speed's practising certificate had expired, so it terminated his employment. He was then deported after Immigration New Zealand said he could stay only if he had a job.

Speed complained to the authority that his dismissal by the school was unjustified, an investigation into his misconduct was unfair, and information provided to the Teachers Council by the school put him at a disadvantage.

But the authority disagreed, saying dismissal over a failure to hold a practising certificate was a "straightforward procedure".

The school had sought a contribution towards the $18,250 cost it had incurred from the matter, which included a two- day hearing.

Shortly after being deported, Speed told Fairfax that he still loved New Zealand and wanted to return.

"I have made some mistakes but I don't think I deserved what happened.

"It is a nightmare that this has snowballed."

- © Fairfax NZ News