Washington CNN  — 

A sweeping report released Monday by the Justice Department’s internal watchdog debunked several key claims and conspiracy theories that President Donald Trump repeatedly used to attack the Russia investigation that overshadowed much of his presidency.

The 476-page report from the Justice Department’s inspector general, an independent internal watchdog who is respected across the political spectrum, demonstrates how Trump relied on unsubstantiated theories and blatant falsehoods to hammer away at the Russia investigation.

At the same time, the review did uncover serious problems with some elements of the probe, such as the surveillance of a Trump campaign aide. These findings give Trump enough material to claim victory. On Monday he said the report was “‘far worse than I would have ever thought possible.”

The inspector general, Michael Horowitz, was appointed by President Barack Obama and confirmed without opposition in the Senate in 2012. He has previously worked under Republican administrations and is respected in Washington as an apolitical fact-finder.

Here’s how the report assessed seven Trump claims about the Russia investigation.

Claim: The Russia probe shouldn’t have been opened

In July 2016, amid a flurry of contacts between the Trump campaign and Russians, the FBI launched an investigation codenamed “Crossfire Hurricane,” which is now generally referred to as the Russia investigation. That probe was later inherited by special counsel Robert Mueller, who uncovered dozens of additional contacts but didn’t find a conspiracy of election collusion.

Throughout his presidency, Trump claimed the Russia probe was an “illegal witch hunt” with no legitimate basis. When Mueller wrapped up in March, Trump said it was “an investigation that should have never happened.” He also said the probe was “a waste of time for our country.”

Facts First: Trump was wrong – the Russia investigation was justified. The inspector general concluded there was “sufficient” evidence for the FBI to open the investigation in July 2016.

According to the report, the FBI launched the investigation after receiving a tip from a trusted foreign government that Trump campaign adviser George Papadopoulos had early knowledge of Russian election meddling. (The country wasn’t named in the report, but it was Australia.)

“Given the low threshold” to open an investigation under Justice Department guidelines, the information from the Australians “was sufficient to predicate the investigation,” the report said.

“This information provided the FBI with an articulable factual basis that, if true, reasonably indicated activity constituting either a federal crime or a threat to national security, or both, may have occurred or may be occurring,” the report said, adding that the investigations into Trump campaign associates Paul Manafort, Michael Flynn and Carter Page were similarly justified.

Claim: The Steele dossier triggered the investigation

Another flashpoint in the Russia investigation was the role of the “Steele dossier,” a collection of private intelligence memos written by retired British spy Christopher Steele. The memos alleged that Trump’s campaign was coordinating with Russian operatives to win the 2016 election. The FBI got its hands on some of Steele’s reporting during the early stages of the Russia probe.

Trump has exaggerated the role of the dossier, falsely claiming that it was why the FBI opened the Russia investigation in July 2016. Trump said the dossier was used to “start things,” and later tweeted that “the entire Russian probe is based” on Steele’s work. He also claimed the dossier “was responsible for starting the totally conflicted and discredited Mueller Witch Hunt.”

This claim was already disproven by Mueller and a report from House Republicans, which both said the Russia probe was launched because of the Papadopoulos tip – not the dossier.

Facts First: Trump’s false claim about the origins of the Russia investigation was refuted yet again. The inspector general’s report said unequivocally that FBI officials hadn’t even seen Steele’s memos when they opened the investigation.

The inspector general said he reviewed more than 1 million documents and interviewed more than 100 witnesses, and didn’t find anything to indicate that “any other information” beyond the Papadopoulos tip, “was relied upon to predicate the opening of the (Russia) investigation.”

Additionally, the report said the FBI officials who opened the probe “did not become aware of Steele’s election reporting until weeks later and we therefore determined that Steele’s reports played no role in the Crossfire Hurricane opening,” referring to the investigation’s codename.

Claim: Top FBI officials were biased against Trump

When the investigation was launched, it was overseen by FBI Director James Comey, his deputy Andrew McCabe and Peter Strzok, who led the FBI’s counterintelligence section.

All three men were embroiled in controversies: Comey for his handling of the Hillary Clinton email investigation, McCabe for possibly lying in a past inspector general review, and Strzok for exchanging anti-Trump text messages with an FBI lawyer. (McCabe is now a CNN contributor.)

Trump accused all three men of “corruption,” and said their scandals were proof that the Russia investigation was motivated by political bias. Last year, he said, “the top people were horrible, you look at what happened, they were plotting against my election.” He also said the collusion allegations against his campaign were “all made up by this den of thieves and lowlifes.”

The President has also vilified former FBI lawyer Lisa Page, who had an affair with Strzok, and also expressed anti-Trump sentiments, while they were involved in the Russia investigation. Page broke her silence last week, calling Trump’s comments “sickening” and “intimidating.”

Facts First: The report exonerated top FBI officials and eviscerated Trump’s accusation that they orchestrated a political take-down because they didn’t want him to win the election.

“While Strzok was directly involved in the decisions to open Crossfire Hurricane and the four individual cases (into Papadopoulos, Flynn, Manafort and Page), he was not the sole, or even the highest-level, decision maker as to any of those matters,” the report concluded.

Despite Trump’s relentless attacks against Comey and McCabe, they weren’t even part of the decision to open the investigation. That fell on Strzok’s boss, assistant FBI director Bill Priestap.

“We concluded that Priestap’s exercise of discretion in opening the investigation was in compliance with Department and FBI policies, and we did not find documentary or testimonial evidence that political bias or improper motivation influenced his decision,” the report said.

The watchdog also found that Page “attended some of the discussions regarding the opening of the investigations” but “she did not play a role in the decision” to launch any of the probes.

Claim: The FISA warrants against Page were improper

While Trump exaggerated the role of the dossier, it’s true that the controversial memos influenced the Russia probe. Steele had worked with the FBI before, and the bureau included some of his information in an October 2016 application to wiretap Page. Federal judges approved the warrant, under the Foreign Intelligence Surveillance Act, or FISA for short.

Trump and Page decried the surveillance, even though it was court-approved. Trump claimed it was “illegal” and an example of “potentially massive FISA abuse.” Trump also said there was “little doubt that the Department of Justice and FBI misled the courts” that granted the warrants.

“They used him to try and spy on the campaign,” Trump said earlier this year, referring to Page, even though Page had cut ties with the campaign before the first FISA application was filed.

Facts First: This might be where Trump was most accurate. The report said there wasn’t proof that the FISA process was motivated by political bias, but there were serious errors and mistakes with how the applications were prepared. For one, the FBI omitted exculpatory information from the FISA court, which could have affected the decision to approve the surveillance.

The US government surveilled Page for nearly a year. The first FISA was granted in October 2016, and the FISA court approved three renewals. The inspector general said his exhaustive review unearthed “significant inaccuracies and omissions in each of the four applications.”

“We found that members of the Crossfire Hurricane team failed to meet the basic obligation to ensure that the Carter Page FISA applications were scrupulously accurate,” the report said.

The report slammed a low-level FBI lawyer who altered an email that affected the FISA process. Before 2016, Page had provided information to a US intelligence agency about his Russian contacts. But the FBI lawyer doctored an email to say that Page was “not a source” for the government, so Page’s past work for the US was never disclosed in the FISA applications.

That FBI lawyer, who was not named in the report, is currently under criminal investigation.

This was perhaps the most damaging section of the report for the bureau. FBI Director Chris Wray said in a letter released Monday that he was ordering more than 40 “corrective steps” to fix the problems.

Claim: The FBI tried to infiltrate the Trump campaign

In addition to FISA surveillance, the FBI used informants to secretly question people associated with the Trump campaign who were under investigation for their Russian ties. One informant, Cambridge professor Stefan Halper, met with Page and Papadopoulos in 2016.

Attorney General Bill Barr has said this all meant the FBI was “spying” on the Trump campaign. Trump gave the controversy a nickname – “spygate” – and spread the questionable allegations on Twitter and in interviews, saying it was “probably one of the great criminal acts of all time.”

The President went one step further. He claimed, without evidence, that an FBI informant was “implanted, for political purposes, into my campaign.” Last year, he publicly asked the Justice Department to determine whether the FBI “infiltrated or surveilled the Trump Campaign for Political Purposes,” and suggested that it may have been ordered by the Obama administration.

Facts First: These claims from the President were debunked by the inspector general report. The review found “no evidence” that the FBI placed informants or spies within the Trump campaign, and that the FBI wasn’t biased when it did use informants as part of the probe.

“We found no evidence that the FBI placed any (confidential human sources) or (undercover employees) within the Trump campaign or tasked any (confidential human sources) or (undercover employees) to report on the Trump campaign,” the report concluded.

The inspector general also “did not find documentary or testimonial evidence that political bias or improper motivation influenced the FBI’s decision” to use informants to interact with Page, Papadopoulos or another top Trump campaign official who was not named in the report.

Claim: Mifsud secretly worked for US intelligence

The FBI investigation began after the Papadopoulos tip. He bragged to a foreign diplomat that he knew Russia was willing to help the Trump campaign by releasing damaging emails about Clinton. The diplomat passed that information to the FBI in July 2016, and the rest is history.

Papadopoulos knew about the Clinton emails because he was told by Joseph Mifsud, a Maltese professor with “substantial connections” to the Kremlin, according to the Mueller report.

But Papadopoulos and Trump-friendly news outlets have pushed an alternate narrative. They claim Mifsud was actually working for US intelligence agencies during his interactions with Papadopoulos, and that he mentioned the Clinton dirt as a ploy to entrap the Trump campaign.

On two occasions this year, Trump re-tweeted video clips containing some of these theories. Papadopoulos has tweeted about it more than a dozen times, calling Mifsud a “CIA/FBI asset.”

Facts First: Zero credible evidence has emerged to back up these conspiracy theories. The inspector general found “no evidence” that Mifsud was working for the FBI in any capacity.

The inspector general said his team reviewed the FBI’s “Delta files,” which contain records on all FBI informants. When they looked for Mifsud, they came up empty, the report said.

“The FBI’s Delta files contain no evidence that Mifsud has ever acted as an FBI (confidential human source), and none of the witnesses we interviewed or documents we reviewed had any information to support such an allegation,” according to the inspector general report.

The review also found no information indicating that “Mifsud’s discussions with Papadopoulos were part of an FBI operation.” CNN previously reported that the inspector general consulted with US intelligence agencies and John Durham, the US attorney whom Barr tasked to also review the Russia probe, and still couldn’t find any information to back up these claims.

Claim: Bruce Ohr acted as a backchannel to Steele

As the Russia investigation intensified last year, Trump turned his fire against Bruce Ohr, a career Justice Department official who is known for taking on Russian organized crime.

The little-known official was suddenly in the spotlight because of his connections to Steele, which predated the Russia investigation. Before the election, Ohr brought some of Steele’s information about Trump to the FBI, even though he wasn’t working on the Russia investigation. Not only that, but Ohr’s wife worked for the company that hired Steele to write the dossier.

“Bruce Ohr is a disgrace, with his wife Nellie,” Trump said on the White House lawn last year. “For him to be in the Justice Department, and to be doing what he did, that is a disgrace.” The President also called Ohr a “creep” and accused him of “helping… Steele find dirt on Trump.”

Facts First: The inspector general criticized Ohr’s actions and said he made “consequential errors in judgment.” He was demoted in 2017 for not reporting his contacts with Steele. But those interactions had no impact on the start of the Russia probe, as previously explained.

Ohr’s first mistake was “failing to advise his direct supervisors” that he was communicating with Steele, “and then requesting meetings with the FBI’s Deputy Director and Crossfire Hurricane team on matters that were outside of his areas of responsibility,” the report determined.

Secondly, Ohr erred by “making himself a witness in the investigation by meeting with Steele and providing Steele’s information to the FBI,” according to the inspector general report.

CNN’s Olanma Mang, Giulia McDonnell, Sam Fossum, Holmes Lybrand and Tara Subramaniam contributed to this story.