One of New Zealand's most respected authors has criticised Auckland University for minimising the seriousness of the Witi Ihimaera plagiarism controversy.

Ihimaera admitted tracts of his latest novel, The Trowenna Sea, had drawn on work from other writers without acknowledgement.

Ihimaera said the offending passages amounted to less than half a per cent of the novel, but respected author CK Stead said that was beside the point.

"It's really like saying'well yes I did steal from 16 people but I only took a dollar from each'," he told Radio New Zealand.

"You haven't harmed them much, but you've harmed yourself enormously."

Stead, who is a professor emeritus of the same university, said he was disappointed at comments from Associate Prof Crosthwaite minimising the seriousness of the fault.

He said students had it hammered into them that they must acknowledge borrowed work and not pass work off as their own.

"You reject students' essays for doing this and you fail them in exams for doing it.

"It makes you wonder what the title of a distinguished professor means in the University of Auckland if they then say what Witi Ihimaera has done doesn't matter."

Stead said the situation would reflect badly on the university until professors acknowledged the seriousness of what had happened.

Ihimaera has said he will be buying back all remaining stock of the novel and planned to republish it.

The edition would contain a new section by the author explaining the background and making full acknowledgement to writers whose work had been drawn on.

"I have taken this step to preserve the mana and integrity of the novel," Ihimaera said yesterday.

"Although I have already made the relevant apologies and have publicly undertaken to fully audit the book myself, it seemed appropriate to remove the first edition immediately and begin working on a corrected second edition."

Ihimaera was a professor of English and distinguished creative fellow in Maori literature at Auckland University.

University dean of arts, Associate Professor Jan Crosthwaite, said while concerning, Ihimaera's actions were not deliberate.

Ihimaera was this week named as one of five Arts Foundation laureates for 2009.

The award gives the recipients a $50,000 no-strings attached donation to celebrate their past achievements and invest in their future.

The Arts Foundation said it has had an assurance from Ihimaera that the money would not be used for his book buy-back.