The personal details of world leaders travelling to Australia for the G20 summit were mistakenly emailed to a member of the Asian Cup football local organising committee, a report said on Monday.
Australia's immigration department confirmed there had been a data breach, but gave no details and did not say whether the world leaders had been informed.
"The breach was immediately referred to the Office of the Australian Information Commissioner," a spokeswoman for the Department of Immigration and Border Protection said in a statement.
"The data was immediately deleted by the recipient and was not distributed further."
The Guardian reported that an Australian immigration official accidentally emailed the passport numbers, visa details and other information about world leaders including Barack Obama and Vladimir Putin to an Asian Cup organiser on November 7.
Other leaders who came to Brisbane for the November 15-16 event and whose information was exposed included British Prime Minister David Cameron, German Chancellor Angela Merkel and Chinese President Xi Jinping, it said.
The Guardian said details obtained under Australia's freedom of information laws showed that data relating to 31 international leaders was mistakenly emailed to the wrong person due to human error.
The mistake arose after the immigration worker failed to check that the autofill function on the email system had addressed the email correctly, it said.
Australia hosted the Asian Cup in January.
The Australian immigration spokeswoman said the department had reviewed and strengthened its email protocols to limit and contain future breaches.
Source: AFP