Federal prosecutors in New York are investigating National Enquirer publisher American Media Inc. for its handling of a story about Washington Post owner Jeff Bezos that may have violated an earlier cooperation deal, according tomultiple reports.

In a remarkable blog post published Thursday evening, the billionaire Amazon founder accused AMI CEO David Pecker of attempting to blackmail him with “intimate” pictures. The publisher allegedly aimed to convince Bezos to kill the Post’s investigations into AMI and its business dealings, or risk his personal photos being published for the world to see.

“Rather than capitulate to extortion and blackmail, I’ve decided to publish exactly what they sent me, despite the personal cost and embarrassment they threaten,” Bezos explained.

Amid the flurry of attention over the blog post, journalist Ronan Farrow chimed in to accuse AMI of trying to blackmail him, too. Farrow said the publisher targeted “at least one other prominent journalist.”

Federal prosecutors confirmed in December that they had granted Pecker and AMI immunity in their investigation into hush-money payments made prior to the 2016 presidential election by former Donald Trump fixer Michael Cohen. Precise terms of that agreement, however, were not publicized.

According to the Associated Press, the agreement stipulated that the publisher commit no crimes for three years.

Yet in his Medium blog post, titled “No thank you, Mr. Pecker,” Bezos laid out a series of startling emails he says he received from AMI representatives. They included a threat allegedly sent from the publisher’s chief content officer, Dylan Howard, about nine sensitive images including a “d*ck pick.” Howard was also involved in the Cohen investigation and immunity deal.

Cohen was sentenced to three years in prison last year after pleading guilty to multiple criminal charges including two campaign finance violations. One of those counts involved AMI ― the publisher had admitted to paying $150,000 to a former Playboy model for the rights to her story about an alleged affair with Trump. The publisher then sat on the story, preventing damage to the Trump campaign.

Pecker and Trump are longtime friends.

An investigator for Bezos told the Post that he believed that sensitive texts previously published by the National Enquirer were leaked by the brother of Lauren Sanchez, a former TV anchor in a relationship with Bezos, who is divorcing his wife. The brother is said to be a Trump supporter. It is not clear whether he might be responsible for leaking the photos as well.

According to Bezos, Pecker was “apoplectic” about a Washington Post investigation into his companies ― particularly research being done on links between AMI and the Saudi royal family. The publisher demanded that the Post owner release a canned statement claiming there is “no knowledge or basis for suggesting that AMI’s coverage was politically motivated or influenced by political forces,” Bezos said.

Other news outlets have reported a connection between AMI and the Saudis in the past. According to AP, the publisher shared an early copy of a one-off magazine extolling the kingdom’s crown prince with the Saudi Embassy in Washington. The fawning publication was widely distributed during the prince’s U.S. tour last year.

AMI said it has launched an investigation into Bezos’ claims of attempted blackmail, but insisted Friday morning that the company had acted “lawfully.”