The ATO is back online but a million gigabytes of data has been wiped from the system

Photo: Darren England/Getty Images.

The Australian Taxation Office (ATO) website is back online today after it crashed on Monday morning.

The ATO website Monday and Tuesday

The tax office said “new hardware storage solution that was upgraded in November 2015” was to blame.

And while the system appears to be fully restored as of 7.10am AEDT, the ATO is still trying to recover a million gigabytes worth of data, according to Fairfax.

Its not known what data has been lost but the ATO said: “No taxpayer information has been compromised.”

“We understand this is the first time this problem has been encountered anywhere in the world and we are working with HPE to determine the underlying cause,” it said.

Hewlett Packard supplies the ATO with its online services and the government body says it’s working with them to resolve the problems.

It’s the second major failure by a government department’s website this year after the Australian Bureau of Statistics website was taken offline on Census night in August.

Business Insider is waiting to hear back the ATO on what data was lost.

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