Maxim Institute director Bruce Logan says he is embarrassed by a rival New Zealand organisation's claim that he plagiarised work by overseas authors.
Writing in the Fundy Post, on the website of the Association of Rationalists and Humanists, Paul Litterick gives several examples of where Mr Logan's writings contain phrasesand sentences used by others.
In one example, Mr Logan wrote in the Herald of June 2, last year: "We need to remember that Government has nothing to give anybody except what it first takes from somebody, and a Government that's big enough to give you everything you want is big enough to take away everything you've got".
However, the Fundy Post says Mr Logan failed to attribute that to Lawrence W. Reed, president of the Mackinac Centre for Public Policy in the United States.
The Fundy Post said Mr Logan had commented in the Herald of September 30, 2002, on the cause of crime, saying the market economies of the West transformed widespread poverty and degradation to an unprecedented spreading of prosperity.
The words belonged to economist Brian Griffiths and were quoted in a 1984 book, The Kindness that Kills by Digby Anderson.
Asked to comment, Mr Logan said: "I'm embarrassed by this because I have been careless and they've got a point".
"I have a habit of writing things down and forgetting where I get them from and there is so much I write in a run ... it's a bad habit."
However, Mr Logan said Reed's words had become "just part of the way we talk here".
He said he had obtained permission to use comments from the Griffiths essay in another article but the attribution was lost during editing.
The Fundy Post revelations follow those by Russell Brown on his website Public Address that Mr Logan's daughter, Alexis Stuart, had been dismissed as a Christchurch Press columnist on grounds of her plagiarism of her father.
Mr Logan said the website article's tone was to "make us look as silly as possible".
"The Fundy Post says we are a fundamentalist organisation but we are not at all."
The institute is a social research and policy think-tank, and Mr Logan said he still had "plenty to say", though would be more careful about naming his sources.
