Major League Baseball tried to stop publication of a tell-all by an insider that dishes dirt on the sport’s most scandalous secrets, from doping to allegations of human trafficking, The Daily Beast has learned.

The league—which is reportedly under federal investigation—made it clear it wasn’t playing around. It retained the aggressive law firm Clare Locke, which has boasted in the past about “killing stories,” in a failed quest to keep “Baseball Cop” by former league investigator Eddie Dominguez out of stores.

Clare Locke fired off a strongly worded five-page letter to the publisher, Hachette, on Aug. 27, just one day before the book was scheduled to hit shelves, claiming it was “defamatory.”

In the letter, which was reviewed by The Daily Beast, the attorneys wrote that “the appropriate course of action is for Hachette to immediately suspend distribution and publication of the book until such a time it has been fully fact-checked and vetted.”

The letter went on to demand that Dominguez—a founding member of the MLB’s Department of Investigation and a decorated former Boston cop—and his journalist co-authors retain all communications with sources, along with the “complete web browser histories and search history for all those involved in the book.”

“With this letter, you are on formal written notice that MLB (and the individual MLB employees) will hold Hachette fully responsible for all special, reputational, economic, and other damages caused by false and defamatory statements in the book, in promotional materials, in any media appearances by the authors, and in any social media statements,” the letter states.

The husband-and-wife law firm sent a separate letter to Dominguez slamming him as a “disgruntled former employee” and demanding he retain all documents and data related to the book, including his social media posts.

MLB’s Investigations Unit was gutted in 2014, and he was fired along with his two bosses and another lead investigator. Months later, according to the book, the league accused Dominguez of submitting fraudulent receipts for car services—which he denies.

“We do not need to remind you of the circumstances under which your employment with MLB was terminated, suffice to say that MLB considers those circumstances important and enlightening as to your motivations, biases, and overall capacity for truthfulness. We believe that a jury will review those circumstances in a similar light if called upon to evaluate your veracity and culpability for any false and defamatory statements in the book,” the letter to Dominguez said.

Clare Locke has earned notoriety for a certain type of case. Earlier this year, the firm represented now disgraced 60 Minutes boss Jeff Fager, former Today host Matt Lauer, New York Times reporter Glenn Thrush and American Media boss David Pecker in an attempt to influence stories about the men in prominent publications. They have litigated against major media organizations including Rolling Stone, The New York Times, CNN and Gawker.

Major League Baseball did not return a call for comment about the letters sent to Hachette and Dominguez on its behalf.

Hachette, which also declined to comment on the legal threats, did not pull the book, which was published and distributed across the country.

In the book, Dominguez claims that baseball had become rampant with corruption, including human trafficking of Cuban baseball players, gambling, and widespread use of performance-enhancing drugs.

In one chapter, Dominguez recounted how a network of middlemen worked to smuggle promising Cuban prospects into the U.S. with the help of fake identity documents and organized crime.

“ We call it our national pastime and if it is our national pastime, do you want it marred by corruption and scandal? ” — Eddie Dominguez, author of “Baseball Cop”

The book also delves into MLB’s problem with performance-enhancing drugs and Dominguez’s involvement in the investigation of a doping clinic which supplied former New York Yankee Alex Rodriguez. Dominguez alleges that baseball executives tried to interfere with cooperation between MLB’s Department of Investigations and the Drug Enforcement Agency in a doping probe.

Despite the troubling claims and Dominguez’s insider perspective, “Baseball Cop” has failed to attract national publicity beyond a handful of publications. A number of baseball insiders told The Daily Beast some in the media have decided not to cover for fear of angering MLB and losing access.

“I’m dumbfounded by the lack of coverage,” Dominguez, 61, a licensed private investigator, told The Daily Beast.

“I don’t know why. I’ve done podcast and radio interviews. They find what is in the book very interesting and alarming but for some reason it doesn’t seem to have captured the national media or any national baseball writers. We call it our national pastime and if it is our national pastime, do you want it marred by corruption and scandal?

“The use of PEDs (performance-enhancing drugs) and human trafficking—all these [are] issues that are brought up in ‘Baseball Cop.’ MLB have turned a blind eye and that's in the book and that’s what they are most scared of.”

One senior baseball writer, who has not written about the book, told The Daily Beast the lack of coverage was “odd.”

“It should have taken off with all the juicy subplots in there,” said the writer, who asked to remain anonymous for fear of losing access to MLB officials and players.

Dominguez wrote the book with veteran sports investigative journalists Christian Red and Teri Thompson. Thompson, the former managing editor of sports at the New York Daily News said she also found the lack of coverage curious.

“It may say something about the disruption of the media business. There isn’t a lot of examination, much less actual investigative work going on in the sports media these days,” she said. “We feel ‘Baseball Cop’ takes readers deep into the inner workings of baseball as well as illuminates a breaking story—the grand jury investigation into alleged trafficking of international players in major league baseball.”

Sports Illustrated reported in early October that the feds are probing potential violations of the Foreign Corrupt Practices Act and possible human trafficking by MLB recruiters in Latin America.

According to the report, the FBI has documents that show Los Angeles Dodgers recruiters promising to smuggle Cuban prospects to the U.S. through third countries in an attempt to sidestep American immigration laws. Dodgers executives were allegedly so aware of the misdeeds that they developed a matrix to characterize recruiters with descriptions like “mostly just an innocent bystander,” and “criminal; oversees the operation - people and money.”

There have also been questions about how MLB handles sexual assault allegations in the #MeToo era. The Daily Beast reported earlier this month that a minor league player accused of sexual assault was sent home and released by the Dodgers but resurfaced to play for another minor league team soon after.