Auckland University has defended its handling of the Witi Ihimaera plagiarism row, saying it was a relatively small offence.

Vice-chancellor Stuart McCutcheon told all students and staff in an email yesterday that much of the public comment was ill-informed and ignorant of the facts.

The university became aware of the claims of plagiarism on November 3, when Ihimaera revealed he was being investigated by the Listener.

Professor McCutcheon said Ihimaera's head of department, Professor Tom Bishop, found a small amount of material in The Trowenna Sea had been published without attribution or acknowledgement.

"On the basis of his review of the material of concern and Professor Ihimaera's response, Professor Bishop concluded that the material had been inadvertently included in the novel without proper acknowledgement and that the instances were not sufficient to constitute misconduct as defined in [the university's Guidelines for the Conduct of Research]."

Professor McCutcheon said plagiarism in any form was unacceptable and Ihimaera had publicly acknowledged his mistake and repeatedly apologised.

"The book has been withdrawn from sale at considerable financial cost to Professor Ihimaera."

Professor McCutcheon said claims that Ihimaera had been treated differently from a student in the same position were patently untrue.

"The university does not condone plagiarism, but recognises the need to take into account a range of factors such as intention, seriousness and extent," the vice-chancellor wrote.

"Were a small amount of unattributed material to be discovered in a doctoral thesis, for example, the student would be required to rewrite the thesis with appropriate attribution - precisely the action Professor Ihimaera will be taking of his own volition."

Jolisa Gracewood, the Listener reviewer who discovered the unattributed material in The Trowenna Sea, told Radio NZ there were more examples of plagiarism than the 16 the magazine published.

"We stopped looking when we had to go to press with the original Listener story. Since then I've looked again - I don't know if other people have looked as well - but there were certainly more examples."

Gracewood said she thought the university had acted very swiftly when it learned of the plagiarism.

"Universities are not known for their swiftness in most cases, so it was a pretty quick decision they came to that there was really no problem ...

"So I would expect them to go back and have another look at that."

An article in today's Listener quotes Margaret Soltan, a professor of English at George Washington University, in Washington DC, as blogging that the University of Auckland was too quick accepting Ihimaera's word that the plagiarism was inadvertent.

"Pretending it didn't happen is the sort of thing a very provincial university will do."

The magazine reported Penguin is doing its own audit of the book.