FIRST ON FOX: Republican Attorney General Andrew Bailey of Missouri filed a petition in state court on Monday to enforce a civil investigative demand, similar to a subpoena, into the advertising materials of left-wing nonprofit group Media Matters for America.

"Media Matters has used fraud to solicit donations from Missourians in order to trick advertisers into removing their advertisements from X, formerly Twitter, one of the last platforms dedicated to free speech in America," Bailey wrote in the petition, first obtained by Fox News Digital. 

In November, Media Matters published a report that said X would place ads next to "pro-Nazi" content. Elon Musk, owner of X, filed a lawsuit against Media Matters, saying the group falsely and deceptively manipulated the algorithm on X. In his filing, Bailey said, "through coordinated, inauthentic behavior" in an attempt to "defame the organization and cause advertisers to pull their support from the platform, thus harming free speech,"

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"Media Matters has pursued an activist agenda in its attempt to destroy X, because they cannot control it," Bailey wrote in Monday's petition. 

After Media Matters published its report, companies like IBM, Disney, Apple, Sony, Walmart, among others, pulled their advertisements from the social media platform. 

"Missourians will not be manipulated by 'progressive' activists masquerading as news outlets, and they will not be defrauded in the process," Bailey wrote.

According to its website, Media Matters is a "progressive research and information center dedicated to comprehensively monitoring, analyzing, and correcting conservative misinformation in the U.S. media."

The petition seeks permission from the court to allow Bailey's office to investigate potential violations of the Missouri Merchandising Practices Act, which includes "any deception, fraud, false pretense, false promise, misrepresentation, unfair practice or the concealment, suppression, or omission of any material fact" in sales, advertisements and solicitation of charitable funds.  

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In a statement to Fox News Digital, Bailey said his office "has reason to believe Media Matters used fraud to solicit donations from Missourians in order to bully advertisers into pulling out of X … so we launched an investigation to get to the bottom of it."

"However, Media Matters has a sordid history of refusing to cooperate with investigations. I’m not going to let this activist group stonewall us," he said.

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"Because Media Matters has refused such efforts in other states and made clear that it will refuse any such efforts, the Attorney General seeks an order from the Court," Bailey wrote.

In November, Texas Attorney General Ken Paxton also opened an investigation into the group for "potential fraudulent activity" after several companies began dropping their advertisements on X. 

Fox News Digital reached out to Media Matters for comment but did not hear back by press deadline.

Fox News' Brianna Herlihy contributed to this report.