NBC News

CANBERRA, Australia — The Australian government launched an investigation Sunday into how a classified booklet detailing Barack Obama's itinerary came to be lost in a gutter during the president's visit last week.

Journalist Dylan Welch of The Age newspaper reported that he found the 125-page booklet on Thursday about 100 yards from Parliament House in Canberra, where Obama attended several functions during his 27-hour Australian visit.

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The booklet contained details on Obama's itinerary, his security convoy and the cell phone numbers of senior U.S. and Australian officials.

Professor Alan Dupont, an analyst based at Sydney University, described the incident as a "significant security breach."

"If that had got into the wrong hands, it would certainly put the president and some of his entourage at risk," Dupont told the newspaper.

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Australia's Attorney-General's Department said in a statement on Sunday it was investigating. The department said it did not comment on security matters.

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The Associated Press and msnbc.com staff contributed to this report.