Labor is outraged that the "robo-debt" program against ordinary Centrelink clients is set to carry on and expand despite the controversy surrounding the policy, while Centrelink's successful partnership with the federal anti-money laundering agency Austrac is set to end in two years when its funding runs out.

The Australian Transaction Reports and Analysis Centre told a Senate Estimates hearing in Canberra on Tuesday that its Centrelink data-matching effort, which has reaped $8 million in recovered money in just six months, against a 12-month target of $3 million, will end in 2019 when its funding runs out.

But the agency was at pains to say it would still be working with Centrelink even after the data-matching program, which is budgeted to cost $2.9 million this financial year and $2.7 million in 2017-2018, winds down.

The program gives Centrelink access to Austrac's database of "significant or suspicious financial transactions" with the information "used to detect undisclosed income or target unexplained wealth".

In its first six months, the partnership detected more than $8 million in dodgy welfare payments or debts, against an annual target of $3 million.

In the wake of the Estimates hearing, Labor's human services spokeswoman Linda Burney, a vocal critic of "robo-debt", was on the attack, accusing the government of abandoning its effort against serious criminals while stepping up its targeting of ordinary Centrelink clients.

"This move flies in the face of the tough on welfare fraud rhetoric used by [Human Services Minister] Alan Tudge to justify his robo-debt system," Ms Burney said.

"The Turnbull government has its priorities all wrong, targeting honest hard working Australians and scaling back measures to identify criminal activity.

"That simply doesn't make sense"

But Mr Tudge's office rejected the criticism, saying Labor had got it wrong and the funding was in place to build a permanent capability to catch serious fraudsters which would continue to operate after the budget commitment ceased in 2019.

Ms Burney's colleague, Labor's justice spokesperson Clare O'Neil, joined the criticism, saying criminals were going to get a "free kick" from the funding cut.

"The government must explain why it is cutting funding to this program," Ms O'Neil said.

"Only this government would launch a misguided attack on hundreds of thousands of ordinary Australians while giving serious, fraudulent criminals a free kick.

"Financial crimes require considerable expertise to investigate, it is deeply concerning that this program could be ended leaving the welfare system open to abuse."

The unexpected success of the data-matching program came despite the Department of Human Services, which runs Centrelink, being able to process fewer than half the number of cases it hoped for, blaming a lack of trained staff.

The department says it carried out 287 reviews using the Austrac data, well short of its target of 626, because it did not expect the analyses and investigations to be so complex and time-consuming.

The department says it expects even better results after hiring financial specialists and streamlining its processes.