MINNEAPOLIS — The Minneapolis Star Tribune’s film critic has resigned in the face of plagiarism accusations, the newspaper reported in an apology to its readers.

The newspaper on Tuesday said it was tipped by a reader and confirmed instances in which Colin Covert’s reviews included unique phrases previously used by writers for several publications, including The New York Times, Paste Magazine, vulture.com, The Wall Street Journal, IndieWire and Hollywood Reporter.

“Using distinct phrasing from other authors without attribution is a form of plagiarism and is a violation of our journalistic standards and ethics and those of our industry,” the newspaper said in its statement.

Covert had been a staff writer at the Star Tribune for more than 30 years. His questioned reviews span many years and include one as recent as last month.

The newspaper published a statement from Covert in which he apologized for compromising what he called the Star Tribune’s “meticulous reputation for integrity.” He thanked the paper for his career and said: “When blunders occur it is proper to admit them, correct them and move on.”

The Star Tribune apologized to the writers and publications from which Covert took material. The newspaper said it also is removing all of Covert’s work from its website and alerting wire services and syndicates that use his reviews.

The Associated Press has distributed to its members some of Covert’s stories for use in their own publications. The AP is trying to determine whether there are any problems with those stories.