The Anzac spirit has taken a knock following a Kiwi journalist's comments that Australian World War I soldiers were bludgers and thieves.

The comments, by journalist Jock Anderson, were made during a Radio New Zealand panel discussion about a new book by former Australian Army officer and Department of Veterans Affairs historian Graham Wilson.

In Bully Beef and Balderdash, Wilson questions myths surrounding Australia's all-volunteer forces who fought in WWI and WWII - including the legend of the Australian bushman who transformed into natural warrior on the battlefield.

Anderson said that was absolutely a myth.

"The Aussies have been reluctant soldiers at the best of times, and they've been essentially bludgers, some of them - excellent black-marketeers, scavengers, poachers and thieves," he said.