Australian PM promises 'heads will roll' over census

Prime Minister Malcolm Turnbull assures Australians their census information is safe

Australia's prime minister has promised "heads will roll" after an online attack left millions of people locked out the country's census website.

Two-thirds of Australians were expected to complete the national survey online in an ambitious shift from paper.

An investigation is likely to focus on tech giant IBM's efforts to protect the A$470m (£280m, US$360m) project.

The government has been unable to say when the website will be online more than 36 hours after it was shutdown.

It is the latest in a series of headline-grabbing scandals faced by the the government in the weeks after the election.

'Bitterly disappointed'

The Australian Bureau of Statistics shut down the census website after what it said were four "denial of service" attacks.

Prime Minister Malcolm Turnbull admitted that there were "serious failures" with the census and moved to assure people that their data was safe.

"I too am very angry about this, I am bitterly disappointed about this," he told radio station 2GB.

"This has clearly been a failure on the part of the ABS."

Treasurer Scott Morrison and Prime Ministe Malcolm Turnbull during a news conference

A denial of service attack is when hackers orchestrate thousands of compromised computers to overwhelm a website with traffic.

In the lead up to the census, the ABS claimed its servers could handle one million forms per hour.

The prime minister said that "there will be some very serious consequences" following the investigation into the debacle.

One person likely to come under scrutiny will be David Kalisch, the head of the ABS, who receives a salary of more than A$700,000.

'Down for maintenance'

Meanwhile, a personal website for the newly appointed minister responsible for the census appears to have been shut down.

Assistant Treasurer Michael McCormack's personal website displayed the message: "Error 500 - internal server error".

A spokesman for the minister did not answer questions about whether the website had been attacked.

"It's down for maintenance," he told the Australian Associated Press.