The authority also ordered Air New Zealand to pay Mr Foai more than $9000 which had been withheld from his final pay to offset the overpayment.
Mr Foai successfully challenged the determination in the Employment Court, which found in April 2012 that he had received the wages in good faith and had altered his position in reliance on those wages. He was also awarded costs.
The court found Mr Foai had queried his pay a number of times and been reassured it was correct, but the overpayments continued.
Mr Foai told the court that as a result of the higher wages he had moved into new accommodation, went on overseas trips, bought gifts, decided to get married and bought an engagement ring.
He said he naively thought his higher pay may have been because he was now mixing with senior management, including chief executive Rob Fyfe.
"I thought maybe Rob Fyfe would have pulled, you know, some strings or something,'' he said.
The airline sought leave to appeal against the judgement in the Court of Appeal but was declined in August.
Mr Foai, through lawyer Johanne Greally, claimed a total of $30,774.63 for legal costs and disbursements, which was reduced by Judge Anthony Ford to a "reasonable figure'' of $19,500.
He directed Air New Zealand to pay 66 per cent, plus court costs and photocopying, resulting in a total award of $13,355.55.
Mr Foai's employment was terminated in 2009, with the airline claiming a fundamental breakdown of trust and confidence.
The Employment Court judgement of April 2012 said Mr Foai had gained new employment as a court security officer with the Ministry of Justice.
An Air New Zealand spokeswoman said the airline accepted the findings of the Employment Court's judgement made last week in regards to Clint Foai as the conclusion of the matter.
