More than 500 people have had their benefits cut off because they are suspected of fraud or are earning too much.
About 3500 people are being investigated for potential benefit fraud since the Ministry of Social Development and Inland Revenue began sharing information last year.
Of these, 525 people, who received about $5.6 million, have had their benefits immediately cancelled.
Associate Social Development Minister Chester Borrows said the IRD has identified people whose tax rate is higher than it should be to be on a benefit, or whose salaries are too high to qualify for one.
In some cases people have not disclosed their full circumstances.
Mr Borrows said deliberate fraudsters will be discovered and prosecuted.
He said 2300 people are still being contacted about potentially receiving a benefit when they are not entitled to one.
