CANBERRA: Global technology giant IBM carried most of the blame for the crash of Australia's online census three months ago and had compensated the government for the financial cost of the debacle, the prime minister said on Friday.

Australia's first attempt to conduct a census online shut down for 43 hours in August after the website failed to cope with routine denial-of-service attacks.

Prime Minister Malcolm Turnbull said IBM, the Australian Bureau of Statistic's head contractor, had reached a "very substantial" confidential settlement with the government over the failure that "absolutely" covered costs.

"It would not be an exaggeration to say that we had a collective sense of humor failure about IBM's performance here and they have 'fessed up (confessed), they've paid up and we're going to learn the lessons of this incident very diligently," Turnbull told Melbourne Radio 3AW.

"Overwhelming the failure was IBM's," he said.

IBM Australia said on Friday the company had no further comment to add to a submission it made to a Senate inquiry last month into the failure.

IBM Australia Managing Director Kerry Purcell told that inquiry he apologized for the inconvenience and took full responsibility for the failure. He blamed a router failure.

Australian Bureau of Statistics boss David Kalisch told the same inquiry that the failure had cost taxpayers 30 million Australian dollars ($22 million).

A report on the failure published on Thursday by Alastair MacGibbon, special adviser to the prime minister on cybersecurity, described the website's denial-of-service protections as "inadequate."

The bureau's "close and trusting relationship" with IBM as a long-term contractor resulted in insufficient independent verification and oversight of critical aspects of the website, the report said.

IBM had been awarded AU$1.55 billion in Australian government contracts since 2013 and the census website contract had been worth AU$9.6 million.

MacGibbon recommended the government establish a "Cyber Boot Camp" where senior bureaucrats could learn cybersecurity fundamentals.

He found that no other information technology failure had done more damage to public confidence in the government's ability to deliver.