Amid more findings of plagiarism in her book The Fitzgeralds and the Kennedys, historian and Harvard Overseer Doris Kearns Goodwin has left “The NewsHour with Jim Lehrer” for an indefinite period of time and found withdrawn her invitation to speak at the University of Delaware’s commencement.

In a statement, “NewsHour” said that “until all outstanding questions are resolved, ‘The NewsHour’ and Doris have mutually agreed that Doris will take a break from appearing on the program.”

Goodwin’s return to the PBS show is not guaranteed.

“Once her situation gets resolved, we’ll take another look,” said Sara Hope Franks, public relations manager for “NewsHour.”

On Tuesday, the University of Delaware withdrew its invitation for Goodwin to speak at their commencement ceremony.

“In light of recent admissions of plagiarism by Doris Kearns Goodwin, the University of Delaware has withdrawn its invitation to her to serve as the speaker at its Commencement,” according to a statement issued by the university.

University of Delaware President David P. Roselle wrote in an e-mail that the decision was based on two considerations and was discussed via phone with Goodwin, who agreed.

“I felt that the probability that she would be placed in an embarrassing situation was unacceptably high from the university’s point of view,” Roselle wrote.

Roselle also said the university was placed in a difficult position of determining whether the recent controversy would detract from the spirit of the ceremony.

“Commencement at our institution is a time reserved solely for a celebration of the successes of the students, and her serving as speaker under the current conditions was likely to add to the agenda for the upcoming commencement,” Roselle wrote.

“We do not want any second agenda item for Commencement.”

Roselle expressed regret about withdrawing the invitation.

“There is no joy in any of this,” he wrote.

Simon & Schuster, the publisher of The Fitzgeralds and the Kennedys, has destroyed all remaining copies of the book in inventory in anticipation of a revised version that will correct the problems with source attribution.

In an article in Saturday’s The New York Times, Goodwin acknowledged copying passages from many more books than had originally been believed.