CANBERRA, Australia, Aug. 10 (UPI) -- The Australian Bureau of Statistics says a series of hacking attacks led to the census website being shut down Tuesday night on the first day people were able to fill out the forms online.
Last Wednesday, the Australian Bureau of Statistics' top statistician, David Kalisch, said the agency was "ready" with "the best security features [for which] you could ever ask."
But six days later, Kalisch said the census website was hacked four times and was shut down as a precaution after the fourth attack. It remained shut down Wednesday.
"It was an attack, and we believe from overseas," Kalisch told ABC NewsRadio, adding it was an attempt to sabotage the census.
Australians were prevented from taking part in the census.
An estimated 16 million people were expected to log on to complete the census Tuesday.
No data was lost.
"The ABS apologizes to the Australian public for inconvenience caused and reassures Australia that no data has been lost or compromised," the agency said in a release. "The ABS has an unblemished record of protection of data and there has never been a breach in relation to census data. The protection of census data has and always will be our first priority.
The Australian intelligence agency is investigating.
Attorney General George Brandis told the ABC the security measures in place were "more than sufficient to protect individual privacy."
People officially have until Sept. 23 to complete the census online, and the agency said people won't be fined for not completing the forms on time.
"There will be no fines for completing the census after August 9. There's still plenty of time to complete the census. Thanks for your patience," the ABS said in a statement.
The ABS had estimated that two-thirds of Australians will fill out the census online for the first time, rather than on paper.
The Labor Party's Andrew Leigh was critical of the decision to go online.
"Cyber attack is a cost of doing business if you are on the internet," he told ABC. "Connect a machine up to the Internet and normally within 15 minutes someone is knocking on your door, trying to get in. Any online system needs to be built to be resilient to this."