BERLIN — A German university has moved to strip the country’s education minister of her academic title after ruling that she plagiarized parts of her doctoral dissertation some 30 years ago.

A body of scholars at Heinrich Heine University in Düsseldorf voted late Tuesday to revoke the doctorate of Education Minister Annette Schavan, a leading member of the governing Christian Democrats and a close confidante of Chancellor Angela Merkel, according to a statement made available on the university’s Web site.

The case against Ms. Schavan represented the second time a member of Ms. Merkel’s cabinet had had such problems with long-ago academic work. In 2011 Defense Minister Karl-Theodor zu Guttenberg, a leading member of the Bavarian-based Christian Social Union, the sister party of Ms. Merkel’s Christian Democrats, left politics after it was revealed that he plagiarized parts of his dissertation.

Ms. Schavan was an outspoken critic of Mr. Guttenberg’s academic failings at the time.

Bruno Bleckmann, a dean at the university, said Ms. Schavan’s failure to attribute certain information properly had “resulted in the general conviction of the faculty council that the former doctoral student systematically and deliberately faked a mental performance throughout the entire dissertation that was in reality not her own.”