The AFP believes changing the Census policy raises concerns about government agencies seeking to consolidate information about Australians that will be attractive for use as a means of social control, according to its Web site.

Smartcard integration aside, Clark is "very confident" about eCensus' security as it has been "thoroughly tested and reviewed by third parties".

Clark won't say which third parties performed the security testing, but believes the ABS has taken "appropriate steps" to minimize fraudulent returns.

The ABS does not have a projected ROI for the A$9 million (US$6.9 million) eCensus project, but expects to see efficiencies as Census collectors will receive a text message to their mobile phones informing them that a form has been completed online, eliminating the need for a return trip to the house to collect the paper documents.

"We're doing it because we're meeting the public expectation of people wanting to interact with the government online," Clark said. "With increasing Internet take-up into the future, eCensus could generate significant savings. It's quicker and faster online and the advantage is if you complete the form online the collector won't have to come back to your house."