The Government claims it has detected thousands of welfare fraudsters who earned too much while on a benefit, though the Labour Opposition is questioning how many have actually committed fraud.
Chester Borrows, Associate Social Development Minister, said more than 3000 people had been found earning too much to claim welfare and some would be prosecuted if fraud was proved.
Six months ago, the Ministry of Social Development and Inland Revenue began sharing data to detect beneficiaries whose taxable income was more than they had declared. This led to 3139 benefits being cancelled, most of them unemployment and sickness, which would have cost the taxpayer $33.7 million a year, based on an unemployment benefit of $206.21 a week.
Labour social development spokesperson Jacinda Ardern said anyone who was defrauding the welfare system should be pursued, though she questioned why the Government didn't commit the same energy to tracking white collar tax fraud.
She also said it wasn't yet clear whether all 3000 people had deliberately misled authorities - welfare overpayments and underpayments were common because beneficiaries' working hours often fluctuated.
Work and Income's website said some beneficiaries could be overpaid if income wasn't declared the same week it was earned.
Asked if benefits may have been accidently overpaid, the minister's spokesman said there was enough information to detect wrongful payments, but more evidence was required to prosecute.