The Times was alerted to the problem by editors at The Wall Street Journal. They pointed out extensive similarities between a Journal article, first published on The Journal’s Web site around 12:30 p.m. on Feb. 5, and a DealBook post published two hours later, as well as a related article published in The Times on Feb. 6.

Those articles described an agreement on an asset freeze for members of Bernard L. Madoff’s family, in a lawsuit filed by a court-appointed trustee. In the Times article and the DealBook post, several passages are repeated almost exactly from the Journal article.

A subsequent search by The Times found other cases of extensive overlap between passages in Mr. Kouwe’s articles and other news organizations’. (The search did not turn up any indications that the articles were inaccurate.)