The Federal Government is cracking down on dole cheats by allowing Centrelink investigators easier access to welfare recipients' private bank accounts.
Human Services minister Joe Ludwig on Saturday provided details of a $138m initiative to clamp down on welfare fraud.
The program, which was announced in Tuesday's budget and fleshed out on Saturday, is expected to save taxpayers at least $600 million over the next four years.
It will build on an existing pilot initiative between the Federal Government and the Commonwealth Bank, which allows Centrelink investigators to data-match the files of suspicious customers with their bank accounts.
The pilot program, which was established in 2006 under the previous Howard government as part of a Centrelink computer upgrade, proved so successful it netted savings of $405.8m over five years instead of the projected $184m.
The savings were mainly attributed to a reduction in payments following the discovery of increased assets and incomes owned by some customers.
The new initiative will cast the net further; allowing Centrelink to cross-match data with other financial institutions as well as with the Australian Tax Office (ATO).
The new measures will begin on July 1 with the bank accounts of an additional 41,500 people expected to be reviewed over the next four years.
An extra 278,000 tax file reviews will also be made during that time.
"The Australian Government is serious about cracking down on welfare fraud," Senator Ludwig told reporters in Brisbane.
"I am sure everyone would agree that welfare cheats should be pursued, we should be able to see that the commonwealth's taxpayers' money is protected.
"What this is about is ensuring people who need assistance, gain assistance from Centrelink."
Senator Ludwig said trained investigators would only cross-match the data of suspicious files identified by staff or via the 111,600 tip-offs made to Centrelink each year.
"Centrelink doesn't go in and spot check on anyone," he said.
"There is no spying, we work with the customers all the time.
"As you would expect, where there are suspicions of fraud or welfare cheating going on, the Australian Government, through Centrelink, does have the power to request information from ... financial institutions."
But Opposition leader Brendan Nelson said he thought the initiative had gone too far.
"It now seems that they're wanting to have some sort of big brother power in relation to the banks and I think that's going a bit too far," Mr Nelson told reporters in Sydney.
"Every person in this country is entitled to at least a minimum level of privacy."
Civil libertarians said the program discriminated against the poor.
"People who are on welfare have as much right to privacy in relation to their bank accounts as the well-off do," said Australian Council of Civil Liberties president Terry O'Gorman.
"We object to wholesale checking of bank accounts simply because you are on welfare."
Mr O'Gormon called on those banks not yet part of the scheme to resist the push.
"I think the other banks should stand up to the Government," he said.
"Banks are entitled to guarantee their customers' privacy unless, as there is with policing, there is access given only where the state shows there is reasonable cause to believe that welfare fraud is occurring."