The Justice Department inspector general has determined all four Foreign Intelligence Surveillance Act warrants against onetime Trump campaign aide Carter Page were illegally obtained, attorney Joe diGenova said this week.

In an investigation that began last year, Inspector General Michael Horowitz examined the DOJ's and FBI's compliance with legal requirements, as well as policies and procedures in applications filed with the U.S. Foreign Intelligence Surveillance Court related to Page as part of a larger counterintelligence inquiry into President Trump's campaign.

Back in May, diGenova, a former U.S. attorney for the District of Columbia, said the three FISA warrant extensions against Page were illegally obtained, adding, "The only question now is whether or not the first FISA was illegally obtained."

Now diGenova says Horowitz made the same determination about the warrant that started it all.

“I can report categorically that the inspector general has found that all four FISA warrants were illegal. They were based on false information supplied to the FISA Court. And Michael Horowitz has concluded that all four FISA warrants were illegal," he told WMAL on Monday.

The announcement comes days after the Hill's John Solomon reported Horowitz had completed his investigation and, after a declassification period, the report could be released sometime between mid-September to early October.

DiGenova previously said memos, obtained by conservative group Citizens United through open-records litigation, suggest the FBI might have misled the Foreign Intelligence Surveillance Court in the first warrant application about an unverified dossier.

The dossier, compiled by British ex-spy Christopher Steele, contained salacious and unverified claims about Trump's ties to Russia. It was used by the FBI to obtain the authority to wiretap Page, an American who had suspicious connections to the Russians. The first warrant application was submitted in October 2016, after which there were three renewals at three-month intervals, including in January, April, and June 2017.

The warrant applications were approved by a number of high-ranking officials, including former FBI Director James Comey, former FBI Deputy Director Andrew McCabe, former Deputy Attorney General Rod Rosenstein, and former Deputy Attorney General Sally Yates.

The memos obtained by Citizens United, and shared with the Washington Examiner, show Steele met with Deputy Assistant Secretary of State Kathleen Kavalec on Oct. 11 and admitted he was encouraged by a client to get his research out before the 2016 election, signaling a possible political motivation. The timing of the meeting is notable, as it was 10 days before the FBI used Steele's unverified dossier to obtain the original warrant to wiretap Page.

DiGenova served as an independent counsel in the 1990s for a case on former President Bill Clinton's passport before he was elected. Last year, it was announced diGenova and his wife and legal partner Victoria Toensing were joining Trump's legal team for the federal Russia investigation, but that plan was nixed within days. He had been highly critical of Mueller's Russia investigation, claiming that Trump had been "framed" by the Justice Department and the FBI, and has spread conspiracy theories about it.

But diGenova appears to have some knowledgeable sources.

In April, he said a "bombshell" report on Comey was imminent that included criminal referrals. Although diGenova's expectation for the report's release in two weeks was off the mark, Comey was criminally referred for his memos memorializing his conversations with Trump. The Justice Department declined to prosecute. In a piece published Wednesday, the Washington Examiner's Byron York confirmed with sources that Horowitz is preparing to release a report on Comey's conduct in the Trump-Russia investigation, separate from the report on alleged FISA abuses.