Senate Judiciary Committee Chairman Lindsey Graham said Friday that U.S. officials received as many as six warnings that dossier author Christopher Steele was an unreliable source of information regarding Donald Trump.

Graham discussed the assessment of Steele during a radio interview with Sean Hannity, but stopped short of describing all of the information regarding the former British spy because much of it is classified.

“There’s four events that I’m aware of, five actually, where the system was informed that Christopher Steele was an unreliable informant when it came to Trump,” Graham told Hannity.

“Some of them I can’t tell you yet until we get this stuff declassified. But I think it’s going to be five; it may be six,” the South Carolina Republican added later.

Republicans have accused the FBI of abusing the Foreign Intelligence Surveillance Act (FISA) by relying on Steele’s unverified reports in applications to wiretap Carter Page, the former Trump campaign adviser.

The bureau obtained four warrants to spy on Page, the first of which was granted on Oct. 21, 2016.

Republicans have said that the FBI failed to disclose that Steele told Justice Department official Bruce Ohr in September 2016 that he was “desperate” that Trump not be elected. The FBI also continued to cite Steele’s information in its FISA application even after cutting ties with the ex-spy on Nov. 1, 2016 after learning about his contacts with the media.

The special counsel’s report severely undercut the dossier, which alleged that there was a “well-developed conspiracy of co-operation” between the Trump campaign and Russian government to influence the 2016 election.

The report said that there was no evidence of a conspiracy, or that any Trump associates acted as agents of Russia.

The report also debunked Steele’s most specific allegation of collusion: that former Trump lawyer traveled to Prague in August 2016 to meet with Kremlin operatives. The special counsel quoted Cohen’s denial that he ever visited the European city.

Republican lawmakers have hinted that days before Donald Trump took office, a top British national security official sent a letter to incoming national security adviser Michael Flynn and outgoing national security adviser Susan Rice casting Steele as an unreliable source. BuzzFeed News had published Steele’s dossier several days earlier.

Graham asserted that the FBI received other warnings about Steele before the first FISA warrant application was submitted.

“You had warnings before you got the first warrant. Then you had more evidence coming in all the way through to the fourth application,” Graham said.

“During that period of time the system continued to receive input that Steele was unreliable. What did they do to assure themselves that they were on the right track?”

Graham spoke with Hannity just as the Justice Department’s inspector general, Michael Horowitz, informed Congress that he has finished his investigation into whether the FBI abused the FISA process. Horowitz submitted the report to the Justice Department and FBI for classification review.

On Aug. 29, Graham called on Attorney General William Barr to declassify nine categories of information related to the FBI’s FISA applications, including details about the FBI’s efforts to verify Steele’s allegations.