The slip-up was discovered almost immediately, after the official was alerted by the recipient, a member of the organising committee of the Asian Cup, held in Australia in January.
However, according to Guardian Australia, new rules requiring departmental staff to type in all email addresses manually were introduced only after it lodged a Freedom of Information request, months later.
In a letter to Australia's privacy commissioner in early November, the director of the department's visa services division wrote that, "given that the risks of the breach are considered very low" and that "actions ... have been taken to limit the further distribution of the email", she did not "consider it necessary to notify clients".
Now, though, the cat is out of the bag, and it seems likely that world leaders are unamused. The official concerned is said to be "mortified". A spokesman for Germany's Chancellor Angela Merkel told Spiegel Online that "the German Government learned about what happened from the press ... The Government has none of its own information about this."
A White House spokesman, meanwhile, told reporters that the United States Administration was looking into the reports, adding: "We'll take all appropriate steps necessary to ensure the privacy and security of the President's personal information." And in India, a senior government official told the Hindustan Times: "We have seen the report and will take necessary action at our end on the matter."
The leak follows another privacy breach by the department, which published personal details about 10,000 people held in immigration detention on its website last year.
It also comes less than a week after federal Parliament passed laws requiring phone companies and internet providers to retain personal data for two years.
Greens Senator Sarah Hanson-Young said: "Only last week the Government was calling on [Australians] to trust them with their online data. This is another serious gaffe by an incompetent Government."
