The Justice Department inspector general’s investigation into the FBI’s surveillance of a former Trump campaign adviser has received last-minute help from multiple witnesses, Fox News reports.

Justice Department inspector general Michael Horowitz sought interviews with the witnesses early in his investigation into whether the FBI abused the Foreign Intelligence Surveillance Act (FISA) in its investigation of the Trump campaign, according to Fox’s Catherine Herridge.

The witnesses’ decision to cooperate comes as the 18-month long investigation is winding down. Texas Republican Rep. John Ratcliffe said last week after meeting with Horowitz that the investigation is complete, and that a report of the probe is being drafted. (RELATED: Texas Rep. John Ratcliffe Says FISA Abuse Investigation Is Complete)

The Fox News report does not identify the witnesses or say when they provided assistance to Horowitz’s investigation, which officially began March 28, 2018.

But one witness who works outside of the Justice Department and FBI began cooperating after Attorney General William Barr appointed John Durham, the U.S. attorney in Connecticut, to lead an investigation of the U.S. government’s surveillance activities against the Trump campaign, as well as the origins of the Russia probe, Fox’s sources said.

Christopher Steele, the former British spy behind the Trump dossier, agreed last month to meet with Horowitz’s team after initially being reluctant to do so. New York Times reporter Matthew Rosenberg said on CNN June 5 that Steele decided to cooperate because he had grown concerned that the FBI was going to throw him under the bus in the Horowitz investigation.

Steele provided information from his dossier to FBI agents, Justice Department official Bruce Ohr, multiple State Department officials, and to several reporters. The FBI cut ties with Steele on Oct. 31, 2016, because he had an unauthorized contact with Mother Jones reporter David Corn.

The FBI relied heavily on Steele’s dossier in four applications for FISA warrants against Carter Page, a former Trump campaign adviser. Republicans have alleged that the FBI misled the FISA court by relying on unverified information from Steele, who was hired to investigate the Trump team by the Clinton campaign and DNC.

The special counsel’s report all but debunked the dossier’s central claim that the Trump campaign took part in a “well-developed conspiracy of co-operation” with the Russian government to influence the 2016 election. The special counsel said it could not establish that anyone on the Trump campaign conspired with the Russian government, or that any Trump associates acted as agents of Russia. Page, who has vehemently denied Steele’s allegations about him, was also not charged in the special counsel’s probe.

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