The White House is investigating reports that President Barack Obama's passport details, with those of other world leaders, were leaked before last November's G20 meeting in Brisbane - and that leaders were not notified about the privacy breach.
The Indian Government is also looking into the leak, after Australia's Department of Immigration admitted that one of its staff accidentally emailed personal information about heads of government who attended the summit - including dates of birth and visa details - to organisers of a regional football tournament.
The embarrassing mistake, which occurred a week before the summit, was caused by the official failing to check the address field on the email, where the autofill function had inscribed the wrong recipient.
Leaders whose personal details were disclosed included British Prime Minister David Cameron, Russian President Vladimir Putin, Chinese President Xi Jinping, Indian Prime Minister Narendra Modi, Japanese Prime Minister Shinzo Abe and Indonesian President Joko Widodo.
Prime Minister John Key, who attended, responded yesterday: "I really don't have any details on that but I wouldn't be overly concerned. I've changed my mobile phone [number] about three or four times since in the time I've been Prime Minister because unfortunately it gets shared quite regularly on the internet."