Ten stories filed to NPR Music and New York-based classical public radio station WQXR contained phrases "copied from other sources without attribution," NPR News Chief Michael Oreskes announced Thursday.

The stories, written by WQXR online editor Brian Wise about performances at Carnegie Hall, contain chunks plagiarized from 17 other articles, according to NPR. Those stories have been collected on a separate page with a note explaining the violation.

Wise was caught by an NPR copy editor, who flagged the plagiarism while going over one of his stories, per Oreskes:

After discovering that some key phrases in the piece had previously appeared elsewhere, the editor alerted newsroom management at NPR and WQXR. A review was then begun of the other 40 pieces Mr. Wise had written jointly for and WQXR since 2008. That review turned up the other instances between April 2011 and the unpublished piece in October 2015. WQXR is in the process of conducting a thorough examination of all of Wise's pieces written exclusively for So far, WQXR has not discovered further instances of plagiarism. WQXR will update its site if it does so.

Wise resigned after the plagiarism was caught, according to the note. He acknowledged the plagiarism Thursday in a Medium post, calling the instances "unintentional" and "entirely my fault."

NPR and WQXR have identified some sentences and phrases in my work that were similar to those used in other media outlets. They are right. These unintentional lapses are entirely my fault. I did not live up to my high standards or those of NPR and WQXR. I sincerely apologize for this.