ROME — The unexpected leak of Pope Francis’ much-anticipated environmental encyclical Monday has meant the return of something that not long ago was fairly common around the Vatican but had become often dormant during the two-plus years of Francis’ mostly charmed papacy: intrigue.

Who leaked it and why? Was this the work of frustrated conservatives in the Vatican, as some experts have speculated? Does it portend big fights at a pivotal October meeting in which Church officials are expected to grapple with homosexuality and divorce? Or is it just a tempest in a teapot?

“Somebody inside the Vatican leaked the document with the obvious intention of embarrassing the pope,” said Robert Mickens, a longtime Vatican expert and editor of Global Pulse, an online Catholic magazine.

The Vatican press office was tense on Tuesday. Hours after a draft of the encyclical was published Monday on the website of L’Espresso, an Italian magazine, the Vatican indefinitely revoked the credentials of Sandro Magister, the journalist who wrote a short introduction that accompanied the magazine’s publication of the draft. Vatican officials say the leaked draft is not the final version of the encyclical, which has been barred from release until Thursday.

Leaks are hardly uncommon in journalism — some would consider them sustenance — and Vatican journalism has been no exception. Most recently, Pope Benedict XVI’s papacy was undermined when his butler leaked documents, in an episode known as VatiLeaks, that exposed infighting and discord in the Vatican. The scandal is considered one of the reasons that Benedict resigned, leading to the March 2013 election of Francis.

With global interest in the Francis encyclical — titled “Laudato Si,” or “Be Praised” — the Vatican had prepared a major media rollout, with a news conference on Thursday morning and the release of the final document. That has now lost some of its steam. Tempers flared inside the Vatican press office on Tuesday, both among staff and a handful of reporters, who criticized others for breaking what they saw as an inviolable promise not to publish before Thursday.

The immediate focus of attention was Magister, who writes a widely read blog about the Vatican on the L’Espresso website and is known as one of Francis’ toughest critics. Magister said he was simply following orders: He wrote a short introduction to the draft after his boss, Luigi Vicinanza, L’Espresso’s editor, got a copy and decided to go public.

“Sure,” Magister said in an interview, “I’m the one who got suspended. I violated a pledge not to break the embargo. So I didn’t object to the suspension.”

Vicinanza said he wrote on Tuesday to the Rev. Federico Lombardi, the Vatican spokesman, explaining that he, not Magister, was responsible for posting the draft. Vicinanza told the Vatican spokesman that he did not feel bound to respect the embargo because he had not received the text from the Vatican. He declined to say where he had gotten it.

“There’s no intrigue, just journalism,” Vicinanza said in a telephone interview.

Many journalists agreed that under similar circumstances, they, too, would have posted the draft. But several Vatican analysts on Tuesday also argued that it was no coincidence that the draft had found its way to Magister. He wrote a June 1 column that criticized the alleged “inspirers” of the encyclical as being advocates of abortion. He has characterized the Vatican media as being soft on Francis, while also criticizing the pope on foreign policy and as being overly fixated on himself.

“The light is all for him, the pope,” Magister wrote in April 2014. “Not the institution, but the person.”

Giacomo Galeazzi, a Vatican expert who writes for La Stampa, a Turin newspaper, said the leak could have come from prelates in the Roman Curia, the governing body of the Vatican, which Francis is trying to reform. In an interview, Galeazzi argued that the pope’s enemies on the outside “want to weaken the encyclical’s message while those inside want to weaken the figure of the pope.”

Galeazzi also noted that L’Espresso had published several critical articles of the encyclical in recent weeks, which he called “a pre-emptive strike to an encyclical that has already broken one record: It is the first to be attacked even before it has been published.”

Alberto Melloni, a liberal scholar and Vatican historian, said the leak reflected the continuing tension inside the Vatican, where some entrenched members of the Curia remain resistant to changes that Francis is trying to pursue. Leaking the draft was a way of demonstrating the Vatican remains in some ways dysfunctional while also tainting Francis’ reformist credentials, Melloni said.

“This shows the daily fight he has to fight,” he said.

The big showdown is expected in October, when Francis will convene a major synod of bishops at Vatican City to discuss issues related to the theme of family. Much is under discussion, including the question of whether divorced and civilly remarried Catholics should be allowed to receive Communion. The synod is expected to be a hotly contested event, and many analysts saw the leaked encyclical as a piece of this larger struggle.

Marco Politi, a Vatican analyst and author of “Pope Francis Among the Wolves,” said tensions had been steadily rising in recent months, especially since Francis delivered a stern address in December, accusing members of the Roman Curia of careerism and hypocrisy. A few months later, Politi noted, documents were leaked showing the expenditures made by Cardinal George Pell, the man appointed by Francis to tighten controls of the Vatican’s budgets.

“This was a sign of this inner battle over the policies of Pell to control all the budgets of the departments,” Politi said.

Despite it all, most analysts doubted that the leak would bring much, if any, damage to Francis. One senior Vatican official took it in stride, playing down any conspiracy theories, while pointing out that journalists just want scoops.

“It has happened before, and it will undoubtedly happen again,” the Vatican official said, speaking on the condition of anonymity to discuss internal matters. “It is not the best situation, but it is not the end of the world.”