Photo taken on May 20, 2018 shows the campus of Australian National University in Canberra, Australia. (ZHU NAN / XINHUA)

SYDNEY - Australia's top-ranked university said on Tuesday hackers breached its cyber defenses late last year to obtain sensitive data of students, including bank account numbers and passport details, going back to 19 years. 

According to World University Rankings, ANU is Australia's best university and many of its graduates go onto to hold senior government positions, magnifying security sensitivities over the data breach

The Australian National University (ANU) said it had only discovered the breach two weeks ago and that it was carried out by "a sophisticated operator", without elaborating. 

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An earlier cyberattack, disclosed by ANU in July last year, had failed to gather sensitive information. 

According to World University Rankings, ANU is Australia's best university and many of its graduates go onto to hold senior government positions, magnifying security sensitivities over the data breach. 

"National community agencies are recruiting directly out of ANU," said Fergus Hanson, head of the International Cyber Policy Centre at think-tank the Australian Strategic Policy Institute. 

"To have information around particular people who are working in different departments...that would be very useful." 

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Australia's cyber intelligence agency said it was investigating who was behind the attack.

"It does appear to be the work of a sophisticated actor," a representative of the Australian Signals Directorate said in an emailed statement.

"It is too early to speculate about connections to other compromises."