Key Points:

Pre-European Maori practised cannibalism but not to consume a dead enemy's mana, says a historian and author.

Professor Paul Moon, who is writing a book on cannibalism, believes the practice had more to do with what he calls "post-battle rage".

In his inaugural address as a professor at Auckland University of Technology he said some believe cannibalism never took place in New Zealand.

They put the eye-witness accounts by early Europeans down to an attempt to justify atrocities carried out.

But if this were true all the whalers, traders, missionaries, settlers and others who came here would have been part of a big conspiracy.

A combination of eye witness accounts, tribal oral histories and archaeological evidence, in which human bones sometimes turn up in middens along with fish and bird bones and other remnants of meals, all leave no doubt in his mind cannibalism took place.

The real question was why it took place and one thing Professor Moon is sure of is it wasn't because people were hungry.

Accounts from early Europeans described big, muscular Maori in good condition. While there may have been periods of hunger from time to time, hunger was not the answer, he said.

More likely was the phenomenon of "post-battle rage."

Professor Moon pointed to recent news footage of unpleasant incidents committed during and after battles in Iraq and a catalogue of atrocities from nearly every major battle of the 20th century.