The tenets of journalism hold that writers aren’t supposed to have a vested interest in the topics they cover — but that if they do, they need to disclose it to the public.

David Brooks appears to have fallen short of those principles.

The veteran New York Times opinion columnist didn’t mention to his readers that he has had a side gig writing for a project funded by Facebook and other donors. Brooks has written favorably about the project, and about Facebook, without disclosing his personal financial connection.

According to BuzzFeed News, Brooks has drawn a salary from the Aspen Institute think tank for his work on an initiative called Weave, which combats social isolation and seeks to build community relationships. The project, which Brooks started, is funded by Facebook and other large donors, including the father of Amazon founder Jeff Bezos, who owns The Washington Post.

Times readers know about Brooks’s work for Weave because he has repeatedly written about it in his column. The problem of social isolation, he wrote in the Times in early 2019, “is being solved by people around the country, at the local level, who are building community and weaving the social fabric.”

But Brooks left out a few important details — namely, that his involvement with Weave is more than just as a volunteer. Facebook funded the project with a grant of $250,000, according to BuzzFeed, and Brooks received a salary from Aspen for his work on it, though it is unclear how much.

Separately, Brooks has penned some supportive words on behalf of Facebook, posted on its corporate site. “Facebook Groups has 1.8 billion users, and more than half of them are in five or more groups,” he wrote in a “guest blog” for Facebook last month. “Clearly people have come to really value the communities they are building online.”

Mainstream news organizations, including the Times, typically require their employees to recuse themselves from writing about or covering entities or people with whom they have a financial or personal connection. Financial reporters, for example, aren’t supposed to cover companies or businesses in which they’ve invested; doing so would probably raise suspicions among readers that the reporting was tainted by self-interest.

When a conflict of interest is unavoidable, news organizations tend to disclose them in the course of their reporting or commentary. The basic obligation is to be “aboveboard” with readers so that they can fairly judge a journalist’s possible motivations and outside influences, said Patrick Lee Plaisance, the editor of the Journal of Media Ethics and a communications professor at Pennsylvania State University.

Brooks’s “failure to disclose [his compensation] undermines a reader’s ability to assess his claims,” Plaisance said. He said it also damages the overall credibility of the Times, which readers expect to act in transparent fashion. “Readers have a right not to feel deceived,” he said.

People at the Times said Brooks informed at least some of his previous bosses about the details of the Weave project. But last summer saw the departure of the Times’s top editorial-page editors, and Brooks’s current editors were unaware of the arrangement. Officially, the Times has declined to say whether it knew about Brooks’s outside employment.

In response to a request for comment, a Times spokeswoman, Eileen Murphy, reissued a statement the company gave to BuzzFeed on Wednesday: “We’re in the process of reviewing David’s relationship with the Weave Project and the Aspen Institute, and what disclosures, if any, should be added to David’s columns going forward.”

She declined to answer follow-up questions. Brooks didn’t respond to a request for comment.

The questions surrounding Brooks follow a string of recent episodes involving Times journalists. Last summer, James Bennet, then the editorial-page editor, resigned under pressure, and James Dao, his deputy, was reassigned over the publication of an op-ed column by Sen. Tom Cotton (R-Ark.) that ignited staff objections. Another staffer, columnist Bari Weiss, quit the paper a short time later, saying in a lengthy resignation letter to publisher A.G. Sulzberger that she had been “bullied” by people inside and outside the Times.

In recent weeks, two Times journalists, Donald McNeil Jr. and Andy Mills, have left amid an uproar over their personal behavior. Separately, the Times cut ties with a freelance editor, Lauren Wolfe, after her tweet about Joe Biden’s inauguration set off a frenzy of conservative criticism on social media.

For decades, many journalists who are associated with a news organization have had secondary sources of income — from writing books to making speeches to appearing on TV news programs. In addition to writing for the Times, Brooks is a pundit on “PBS NewsHour.”

But none of those outside roles necessarily pose a conflict of interest. A “NewsHour” spokesman, Nick Massella, said Thursday that the program was aware of Brooks’s work for the Aspen Institute but not of its funding sources. He said the segments the program has aired about the project and the Aspen Institute don’t warrant further disclosure.

Brooks has written about the Weave project multiple times in the Times. He promoted one of its first events in a May 2019 column, and then reported on the event in another column, which was complemented by photographs taken by a Times photographer. “The people at this gathering are some of the most compelling people I’ve ever met,” he wrote.

At no point, however, has he disclosed Weave’s funders or that he has been compensated by the Aspen Institute. In addition to Facebook, the project’s backers include Miguel Bezos, an Aspen trustee and the father of Jeff Bezos, who donated $300,000 to it, according to BuzzFeed.

Brooks’s guest-blogging on Facebook’s corporate website also did not mention his financial connections to the company. One posting seemed to absolve the social network of complicity in fostering Russian election disinformation, antisemitism, medical misinformation and hoaxes.

“My takeaway from all this research is that it’s not social media that’s the problem, it’s the ideas and behavior of the people who use it,” he wrote last month in his Facebook guest blog.