Labourer Rory O'Mahony (27) said when he asked a bank teller in Dunedin to change an automatic payment date at Christmas so the payment would not default, he was told there was plenty of money in his account.
''It was a bit of a shock.''
When the bank teller located a payment of $1700, the teller asked him if he was a teacher.
''And I said no.''
He had been a teacher's aide ''well over a year ago'' but the payment was nonsensical, he said.
His former employer, St Joseph's Cathedral School, in Dunedin, could not provide him a reason for the payment.
''I've talked to my old boss and she couldn't figure it out. She has no trace of it on the books.''
He has put the money aside but a dishonest person might have spent it, which was a concern, he said.
''The money is sitting there, someone else's money ...
it could be somebody else's holiday pay and they're missing out.''
Ministry chief information officer Leanne Gibson said the reason Mr O'Mahony received the payment was because he was still showing as a valid employee of the school in the Novopay system.
''The money he received belongs to St Joseph's Cathedral School. There is a standard procedure for recovering the money, or he can write a cheque directly to the school for the money that he received.''
All payments made from the Novopay system were to known employees, who could be tracked from information on the system, she said.