CANBERRA, July 12 (Xinhua) -- Tax dodgers are costing the Australian government billions of dollars every year, the Australian Taxation Office (ATO) has revealed.

An ATO audit, released on Thursday, found that the "tax gap," the discrepancy between the amount of tax that Australians should have paid and what they actually paid, was 8.7 billion Australian dollars (6.4 billion U.S. dollars) in 2014-15.

Of that sum, only 500 million Australian dollars (368 million U.S. dollars) was successfully recouped by the ATO despite a major crackdown on tax cheats.

Approximately 9.3 million Australians lodged personal tax returns in 2014-15 but a random analysis of 858 returns found that 72 percent contained errors.

Despite the high rate of errors, the ATO still received 93 percent of the total revenue it expected to receive from taxpayers.

Alison Lendon, deputy commissioner of the ATO, said that while much of the missing money can be attributed to simple errors, there was still a high rate of deliberate tax fraud.

"There is evidence in the community of people obviously wanting to get a big refund and a way to do that is looking at what expenses they can claim," Lendon told the Australian Broadcasting Corporation (ABC) on Thursday.

"We take a harsh view on them, as the community expects."

The audit revealed that 78 percent of returns prepared by tax agents contained an error compared to 57 percent of self-prepared returns.

The ATO has identified 500 agents who "behaved more aggressively" on behalf of their clients, 150 of who will be closely scrutinized this year.