U.S. investigators wiretapped President Trump’s campaign chairman Paul Manafort, according to a report by CNN that vindicates the president’s earlier claims, which were mocked as a conspiracy theory.

President Trump had tweeted on March 4: “Terrible! Just found out that Obama had my “wires tapped” in Trump Tower just before the victory. Nothing found. This is McCarthyism!”

Terrible! Just found out that Obama had my "wires tapped" in Trump Tower just before the victory. Nothing found. This is McCarthyism! — Donald J. Trump (@realDonaldTrump) March 4, 2017

Breitbart News editor Joel Pollak had reported the day before Trump’s tweet that the Obama administration “sought, and eventually obtained, authorization to eavesdrop on the Trump campaign: continued monitoring the Trump team even when no evidence of wrongdoing was found.”

Trump’s claim, and Breitbart News’s report, were mocked as a conspiracy theory, and other news outlets reported that there was no basis to the claims.

CNN itself at the time called the idea that Trump was wiretapped “incendiary.”

But a report Monday evening said U.S. investigators obtained a surveillance warrant on Manafort from a secret court and had monitored him before and after the election, including a “period when Manafort was known to talk to President Donald Trump.”

The report said the secret court that handles the Foreign Intelligence Surveillance Act had authorized a surveillance warrant against Manafort for an investigation that began in 2014, looking into his firm, the Podesta Group, and another firm’s lobbying work for Ukraine’s pro-Russian former ruling party.

“The surveillance was discontinued at some point last year for lack of evidence,” a source told CNN.

However, the FBI then restarted the surveillance after obtaining a new FISA warrant that extended early into this year. The report notably does not say when the new warrant was obtained. Manafort joined the Trump campaign as its chairman in May 2016.

The new warrant was “part of the FBI’s efforts to investigate ties between Trump campaign associates and suspected Russian operatives,” according to the report.

The report notes, “such warrants require the approval of top Justice Department and FBI officials” — but doesn’t specify which top Justice Department and FBI officials had approved it.

Former Attorney General Loretta Lynch and former FBI Director James Comey were leading the agencies, respectively, at the time.

The report said the first warrant had already expired when Manafort had become the chairman in May. Before he left in August, FBI investigators “noticed what counterintelligence agents thought was a series of odd connections between Trump associates in Russia.”

A some point, the FBI obtained the new FISA warrant and began monitoring Manafort again — who has a residence in Trump Tower. The story said it’s “unclear” whether the FBI surveillance took place there.

The Justice Department and the FBI denied that Trump was being wiretapped.

Comey later in March disputed Trump’s claims — in testimony that lawmakers could now find misleading.

He told the House intelligence committee, “With respect to the president’s tweets about alleged wiretapping directed at him by the prior administration, I have no information that supports those tweets, and we have looked carefully inside the FBI.”

The New York Times also reported that Comey had said Trump’s claim was false, and that he had asked the Justice Department to publicly reject it, according to the BBC.

James Clapper, the former Director of National Intelligence, also told Congress that intelligence agencies did not wiretap Trump, nor did the FBI obtain a court order to monitor Trump’s phones, according to the BBC report.