Former FBI agent Peter Strzok, in his memoir released Tuesday, accused Department of Justice (DOJ) Inspector General Michael Horowitz of changing his report on the Hillary Clinton email investigation from a draft that largely was supportive of how Stzork handled himself to the more critical final product after the DOJ and possibly the White House had seen the draft.

Strzok was fired from the bureau after being removed from Special Counsel Robert Mueller's team over anti-Trump text messages sent from his work phone. Those messages, sent to bureau colleague Lisa Page, were a major topic of the nearly 600-page report, which said there was "no evidence that the conclusions by the prosecutors were affected by bias or other improper considerations" but that Strzok's actions "potentially indicated or created the appearance that investigative decisions were impacted by bias or improper considerations."

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Strzok made the accusation in his book, "Compromised: Counterintelligence and the Threat of Donald J. Trump." He said, in a chapter titled "Bait and Switch," that a prior draft of the inspector general (IG) report did not include the part about his texts potentially creating an appearance that the investigation was biased. The Clinton email investigation was codenamed "Midyear Exam."

Peter Strzok is seated to testify before the House Committees on the Judiciary and Oversight and Government Reform during a hearing on Capitol Hill, Thursday, July 12, 2018. (AP Photo/Evan Vucci)

Peter Strzok is seated to testify before the House Committees on the Judiciary and Oversight and Government Reform during a hearing on Capitol Hill, Thursday, July 12, 2018. (AP Photo/Evan Vucci)

"In time I actually found myself looking forward to the public release of the IG's report," Strzok wrote. "By late May the IG had concluded in his draft report that there was no documentary or testimonial evidence of bias in Midyear Exam."

He added: "Those warm feelings toward the IG didn't last long. A little more than two weeks later, I was back in the IG's conference room with [personal lawyer] Aitan [Goelman]. This time I was furious. In the interim, the report had been sent to the DOJ, which meant that its conclusions likely had been seen by the White House too. And now some of its conclusions had been changed."

Strzok went on to write that Horowitz said the changes to the report were a result of the unearthing of additional text messages by Strzok and Page. Among them was an August 2016 exchange in which Page said: " [Trump’s] not ever going to become president, right? Right?!”

Strzok texted back: “No. No he won’t. We’ll stop it.”

The White House, which has been highly critical of Strzok since his text messages were first exposed, rejected the former FBI agent's accusation concerning the IG, DOJ and potentially even the White House.

"This is utter nonsense. Peter Strzok was fired for texting his mistress about the infamous ‘insurance policy,’ exposing his lack of objectivity, clear bias, and hatred of the President of the United States," White House spokesman Brian Morgenstern said in a statement to Fox News. "Strzok perpetuated the Russia hoax, which has been investigated by a special counsel and numerous congressional committees, none of whom have found any wrongdoing by the President. He is now trying to make money selling the same lies for which he was fired. In short, Strzok is a joke, and his book isn’t worth the paper it’s printed on."

Justice Department Inspector General Michael Horowitz looks on as he testifies before the Senate Judiciary Committee on June 18, 2018 on Capitol Hill. (MANDEL NGAN/AFP/Getty Images)

Justice Department Inspector General Michael Horowitz looks on as he testifies before the Senate Judiciary Committee on June 18, 2018 on Capitol Hill. (MANDEL NGAN/AFP/Getty Images)

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Strzok said it was the "We'll stop it" exchange specifically that "seemed to unnerve Horowitz," but defended it based on the timing of when it was sent, while saying he did not remember sending it in the first place.

"Days after Trump's repeated attacks on the immigrant family of Humayun Khan, an army captain who gave his life for our country when he was killed by a suicide bomber in Iraq in 2004, I had expressed my view that Trump would never be elected," he wrote in the book. "In a text that to this day I still do not remember writing, late at night I wrote, 'We will stop it.'"

Strzok continued: "It was an artless comment but conveyed my firm belief that Trump ... would not be chosen by the American people to become president."

He said the texts "triggered Horowitz's apparent risk aversion and caused him to make a fateful and ill-considered edit to the report he had already drafted." Strzok challenged the basis for Horowitz's criticisms of the Clinton probe -- including saying that a delay between when Clinton emails were found on disgraced ex-New York Rep. Anthony Weiner's laptop and when a warrant for the laptop was obtained was simply a result of bureaucratic miscommunication.

He added that accusations the FBI prioritized "Crossfire Hurricane," the investigation into alleged Trump campaign collusion with Russia, over Midyear Exam were unfounded and that even if the FBI had prioritized the Trump investigation it would have been justified because "Crossfire was inarguably a much more urgent and consequential investigation."

Strzok recalled protesting the changes in discussions with Horowitz's team but said it was to no avail.

"None of it made any difference. The IG had made up his mind. I left feeling indignant, defeated, and persecuted," he said. "[I]t was the most irresponsible kind of character assassination perpetrated for the lowest of reasons."

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Strzok also intimated that the changes to the Horowitz report on Midyear Exam could have been the result of Horowtiz being intimidated by Trump or his allies.

"Whether his conclusion was motivated by a fear of having missed something or fear of Trump and his supporters' rage if he failed to back up his narrative, I can't say," Strzok said.

Horowitz's office declined to comment on Strzok's claims. The Justice Department has not responded to a request for comment.

Strzok addressed a number of other topics in his extensive memoir, including his interview with then-Trump national security adviser Michael Flynn, the initial leaks of his text messages with Page to the press and the so-called Steele Dossier.

Fox News' Alex Pappas contributed to this report.