WASHINGTON — A draft copy of a report compiled by the Department of Justice inspector general concludes that the FBI didn’t spy on President Donald Trump’s 2016 campaign, a person familiar with the document confirmed to NBC News.

The information from the inspector general, Michael Horowitz, is expected to be included in the final report that’s due on Dec. 9, according to The New York Times. The Times first reported Wednesday that the report is expected to say that the DOJ watchdog found no evidence that the FBI tried to place informants or undercover agents inside Trump’s campaign.

Trump and his allies have long claimed that his 2016 campaign was spied on. Attorney General William Barr told a Senate Appropriations subcommittee in April that he thought “spying did occur” by the federal government on Trump’s campaign.

“For the same reason we’re worried about foreign influence in elections ... I think spying on a political campaign — it’s a big deal, it’s a big deal,” Barr said in response to a question from Sen. Jeanne Shaheen, D-N.H., who had asked why Barr is looking into the origins of the FBI’s investigation.

A few days later, Trump told reporters, "I think what he said was absolutely true. There was absolutely spying into my campaign. I'll go a step further — in my opinion, it was illegal spying, unprecedented spying and something that should never be allowed to happen in our country again."

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The FBI investigated multiple members of the Trump campaign who were suspected of having ties to Russia, including former Trump adviser George Papadopoulos, who later plead guilty to lying to the FBI about his contact with Russia. But the draft IG report, according to the Times, found that the campaign itself was not under surveillance and that the investigations into the Trump advisers were not illegal or politically motivated.

FBI Director Chris Wray in May said that he would not describe the federal government's surveillance of individuals who worked on the Trump campaign as "spying.”

Asked if he had "any evidence that any illegal surveillance" into the Trump 2016 campaign occurred, Wray said he didn’t.

"I don't think I personally have any evidence of that sort," Wray said.