Deputy Liberal leader Julie Bishop is embroiled in her second plagiarism controversy in a month.
Ms Bishop has reportedly telephoned a New Zealand businessman to apologise that his words have appeared in a new book under her name, without attribution.
Some parts of Ms Bishop's essay are lifted word-for-word from a speech made by businessman Roger Kerr in 1999, according to The Australian newspaper, while in other parts words have been substituted or changed slightly.
The fresh controversy involves Ms Bishop's contribution to `Liberals and Power: The Road Ahead', a book edited by academic Peter van Onselen that is to be published this week.
Dr van Onselen has described the plagiarism as a disappointment.
"Whilst I understand how political offices work, it is still disappointing to learn that Julie Bishop didn't see fit to write herself a chapter in a book that is meant to be about ideas for the future of the Liberal Party," he told The Australian.
Ms Bishop's chief of staff Murray Hansen says the party's deputy leader was not involved, and he took "100 per cent responsibility" for the plagiarism.
Mr Hansen said he wrote the essay and forgot to send footnotes in time for publication.
"I knocked it together very quickly," he said.
"If I'd formatted it and put direct quotes it would have alerted (Ms Bishop) much more quickly to the fact that I was taking large chunks out of someone else's ideas and speech."
In late September, Ms Bishop gave a speech in the parliament which included lines lifted directly - and without attribution - from an article in the Wall Street Journal.