News Corp magnate Murdoch openly criticized Facebook's relationships with publishers last month, saying in a highly publicized statement that the social media giant should pay trusted publishers.
But Murdoch, who had owned once-dominant social media site MySpace, covertly waged war against Facebook over News Feed beginning in 2016, Wired reported, citing unnamed sources.
Murdoch hosted Zuckerberg at his Sun Valley, Idaho, villa and expressed discontent with Facebook's News Feed algorithm and its handling of news.
He requested Facebook consult publishing partners and be more generous sharing digital ad revenue, or he vowed, News Corp executives would take their dislike of Facebook public. He also hinted that News Corp lobbyists would take a more aggressive stand against Facebook with U.S. regulators, as the company had done against Google in Europe.
News Corp denied it would mobilize its journalists against Facebook, although unnamed Facebook executives said they believed at the time that would happen.
It's not a new concern. Facebook has long taken heat for its in-app Instant Articles, which previously did not enforce publishers' paywalls, and which many media organizations discovered generated less ad revenue than articles on their own sites.
The 2016 sit-down between Murdoch and Zuckerberg was apparently the culmination of years of tension.
The two squared off as early as 2007, when Connecticut's then- attorney general, Richard Blumenthal, opened an investigation into Facebook's protection of young users based on letters from concerned parents that referenced predatory accounts.
Facebook at the time believed those accounts were created by lawyers for Murdoch, according to an anonymous former Facebook executive. At the time, News Corp owned the site's biggest competitor, MySpace.
"When it comes to Facebook, Murdoch has been playing every angle he can for a long time," the executive told Wired.
The relationship could be softening, though. Wired reports Zuckerberg toasted to Murdoch late last year at a dinner of Facebook and News Corp executives, speaking highly of his accomplishments and his tennis game.