The report says that McCabe "lacked candour" on four occasions when talking to a Wall Street Journal reporter previous year about the FBI's investigation into a foundation run by Bill and Hillary Clinton, and also neglected to tell his then-boss, James Comey, that he had authorised the disclosure of the information.
On Friday, Mr Trump called the inspector general report a "total disaster" and said "McCabe is controlled by Comey". "No collusion, all made up by this den of thieves and lowlifes!"
It also says McCabe and Comey contradicted one another in their descriptions of how a media disclosure was authorized.
It will also look at the early stages of the FBI's investigation into whether Trump or any of his associates helped Russian Federation interfere in the 2016 election.
McCabe, who was sacked a day short of being eligible to receive his full pension, has loudly complained that his dismissal was unwarranted and politically motivated.
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Irma lashed the Caribbean and the US, making seven separate landfalls as it tore across the islands and the Southeast US. The WMO has a rotating list of names for each Tropical Cyclone basin, such as the Atlantic or Eastern North Pacific.
McCabe, who is close to Comey, could be an important witness for Mueller, who is investigating Trump for possible obstruction of justice, including his motivation for firing Comey in May 2017.
In a blistering statement in March, McCabe framed his firing as being "part of this administration's ongoing war on the FBI and the efforts of the special counsel investigation". It claims that McCabe "lacked candor" on multiple occasions in conversations with federal investigators, according to a copy of the report obtained by CBS News.
The 35-page inspector general report goes into detail in arguing McCabe intentionally misled internal FBI and inspector general investigators about whether he had authorized the disclosure of an August 2016 phone conversation regarding the FBI's Clinton Foundation investigation to The Wall Street Journal.
Responding to the inspector general's report, McCabe said he believed repeated calls by President Donald Trump to fire him had prompted a rush to judgment and an unfair probe into his conduct. During that interview, McCabe again said he didn't authorize the disclosure and didn't know who did. The political action committee for then-Virginia Governor McAuliffe, a Democrat and Clinton ally, donated $467,500 to her campaign, while the Virginia Democratic party gave $207,788, The Journal reported. Though the statement or suggestion was not under oath, it still got McCabe in trouble.
The report on McCabe is part of a larger investigation that the inspector general is doing into decisions and activities within the Justice Department and FBI before the 2016 election.
McCabe contacted the NY official again on November 4 following the publication of another Wall Street Journal article that referred to the information McCabe had leaked.