Last summer, a Voice of America staffer noticed something odd in the radio scripts that a Paris-based freelancer was submitting to editors at the international broadcast service: They were flawless. Despite the fact that the native French speaker stumbled in his second language, his text rendered complicated details in crisp, precise English.

Suspicious, Jason Patinkin started looking more deeply — and found that phrases, sentences and even multiple paragraphs in freelancer Nicolas Pinault’s stories matched those published by other news organizations word for word.

But when Patinkin began sounding the alarm about plagiarism, supervisors at Voice of America took several months before acting on what he had found.

The reaction within VOA was much the same when another staff journalist raised a separate set of plagiarism allegations early last year. Ayen Bior alerted senior officials that scripts submitted by Deirdre Murray-McIntosh, the executive producer of a TV news program Bior co-hosted, used long passages from various websites without credit. The scripts were used in episodes of “Our Voices,” a public affairs and culture program VOA broadcasts to countries in Africa.

In both cases, VOA managers permitted the journalists suspected of plagiarizing material to continue working for months without sanction — and without warning their colleagues there might be a problem, Patinkin and Bior said in interviews. Meanwhile, the problematic reporting remained on VOA’s website without any indication that it was plagiarized.

Pinault and Murray-McIntosh did not respond to multiple requests for comment.

Plagiarism is one of journalism’s cardinal sins; reporters who copy the work of others without crediting or citing their original source are typically suspended or fired. News articles or reports that are found to contain plagiarized reporting are usually flagged with an editor’s note stating what happened.

VOA, which reports from around the world in multiple languages, is a federally funded news organization whose charter obligates it to serve “as a consistently reliable and authoritative source of news” that is “accurate, objective, and comprehensive.”

A VOA spokeswoman, Bridget Serchak, initially declined to address specific allegations when contacted Tuesday. She issued a statement saying, “VOA takes all allegations of plagiarism and any other professional misconduct very seriously. . . . When VOA leadership is in receipt of such an allegation, the issue is thoroughly reviewed and investigated.”

Pressed further about specific instances, she offered additional information several hours later. She said VOA on Tuesday had removed several of Pinault’s archived articles from its website and replaced them with a notice that reads, “The article that previously appeared at this location has been removed because it was found to include what we determined to be plagiarized material.”

The rest of Pinault’s work for VOA — some 82 articles spanning seven years — are “under review” for plagiarism, she said. All of his work since May 2019 has been removed from VOA’s website, with a notification about the review in its place.

Further, after inquiries from The Washington Post, VOA on Tuesday also took down three episodes of “Our Voices” that Bior had challenged. The episodes have been replaced on VOA’s website and YouTube channel with the same notice that appears on Pinault’s plagiarized articles. VOA said it is “reviewing” other episodes.

VOA’s actions on Tuesday came 10 months after Patinkin first raised the issue with managers and 14 months after Bior had first done so, according to emails and other documents they provided. Both had initially alerted VOA’s editor of news standards and best practices, Steve Springer, who investigated their claims last year. At one point in October, Springer told Bior in an email that the examples she had first cited the previous February were “absolutely examples of plagiarism.”

But in a later email, Springer said he wasn’t empowered to take unilateral action and could only make “recommendations” to other managers. None followed up until Tuesday.

Pinault appears to have copied phrases, sentences and paragraphs from stories published by the Associated Press, CNBC, Agence France-Presse and other news outlets in at least five broadcasts and Web articles flagged by Patinkin.

In a story broadcast last fall, for example, Pinault reported on trade tensions between the United States and the European Union. “The transatlantic hostilities have continued since 2004, when Washington declared that a 1992 US-EU agreement governing subsidies in the aircraft industry was dead,” the reporter observed.

Which is exactly what Agence France-Presse reported four days before Pinault. Another Pinault story on Nov. 12, about U.S.-E.U. negotiations over taxation of multinationals, took three paragraphs and a quote from a French official from stories published by CNBC and AFP more than a week earlier.

And in July, seven of the nine paragraphs in Pinault’s story about a dispute between France and Turkey matched in whole or part a previously published report by AFP, simply changing their order. In September, editors found that three of the seven paragraphs from another radio script by Pinault — a news story about E.U. countries accepting refugees displaced by a fire at a migrant camp in Greece — came largely intact from an earlier AFP story.

Patinkin, a former VOA program host who recently left the organization, said in an interview that when he began spot checking Pinault’s work last summer it became clear there was “a pattern” of plagiarism in Pinault’s reporting.

Bior said she “got a feeling” that something wasn’t right about the “Our Voices” scripts during an editorial meeting in 2019. She decided to look into it.

A guest on one program, for example, was described as the founder of “a digital platform that connects worldwide government institutions, training centers and businesses with talented chefs and culinary students from Africa seeking work experience. . . . The visibility and experience of his chefs has allowed Africa’s gastronomic traditions to spread. In 2017, he created an African gastronomy BMA course for IFA Paris, the first course of its kind, to educate a rising group of influencers on African ingredients and teach recipes region-by-region.”

This wording, she found, precisely matched a thumbnail description of the man in a 2018 article in the online Michelin Guide titled “10 Chefs Who Are Changing the World.” Scripts for other shows appear to have lifted language from articles published by CNBC, WomenAfrica.com and other websites.

Bior, who left VOA to join NPR earlier this year, first brought her concerns to Sonya Laurence Green, the chief of VOA’s English to Africa service, in February of 2020. Green referred the matter to Springer. But after months of waiting in vain for a resolution, Bior wrote again in October to Green and Keith Wallace, the Africa division’s executive TV producer.

“I am sending this evidence again in a separate email in hopes that VOA can take it seriously this time around,” she wrote. She copied three other top managers, adding, “so that no one can tell me they didn’t know.”

Green said through VOA spokesperson Serchak that she had no oversight of the program and referred the matter to another part of VOA’s Africa team after Bior first contacted her in February of last year. Wallace did not respond to a request for comment.

Pinault, a freelance correspondent who covered news in Europe and Africa, filed his last story for VOA in April. Serchak, VOA’s spokesperson, said the organization “no longer has a relationship with him,” but offered no details about the circumstances of his departure. She also declined to comment on Murray-McIntosh’s status, saying VOA doesn’t discuss “personnel matters.”

Correction: A previous version of this report included outdated information stating that Green did not respond to a request for comment. Her response is now included.