(CNN) The FBI on Saturday released a redacted version of its previously classified foreign surveillance warrant application on Trump campaign foreign policy adviser Carter Page, which has been the subject of a heated partisan debate over the FBI's tactics investigating members of the Trump campaign.
The FBI released the Foreign Intelligence Surveillance Act warrant application after news organizations and advocacy groups like Judicial Watch sued for its disclosure.
The warrant, which was approved for Page in 2016, allowed the FBI to conduct surveillance on Page. It's been one of the key moves that Republicans have charged is evidence of a pattern of abuse by the Justice Department and the FBI targeting the Trump campaign.
The release itself is significant as it marks the first public disclosure of a highly sensitive FISA request. Information included in the request had been largely reported through two declassified memos released separately by Republicans and Democrats on the House Intelligence Committee, but Saturday's disclosure puts the FBI's own argument in black and white for the first time.
The more than 400-page document released Saturday, which includes the initial October 2016 FISA warrant on Page and three subsequent renewals, is heavily redacted.
It states that the FBI "believes Page has been the subject of targeted recruitment by the Russian government."
"The FBI believes that Page has been collaborating and conspiring with the Russian government," the application states, adding that "there is probable cause that such activities involve or are about to involve violations of the criminal statutes of the United States."
The application says that a significant purpose of the request is to "collect foreign intelligence information as part of the FBI's investigation of this target."
It does have some information about Page's activities, which included a July 2016 trip to Russia in which Page was accused in the opposition research dossier of having met with a top Russian energy official, something Page denies.
Speaking to CNN's Jake Tapper on "State of the Union" Sunday, Page called the accusations against him "so ridiculous."
"You talk about misleading the courts, it's just so misleading," Page said.
The application notes that Page sent a letter to then-FBI Director James Comey to deny the accusation two days after a news story came out stating that Page was under investigation.
Signatures from top FBI and Justice Department officials, including Comey, and Deputy Attorney General Rod Rosenstein appear on each of the four applications.
Page has denied that he ever cut any political deals with the Kremlin.
The FISA warrant that was issued and renewed multiple times for Page was the subject of the memo written by House Intelligence Committee Chairman Devin Nunes that charged the FBI abused its surveillance powers.
Conservative critics of special counsel Robert Mueller have argued that the FISA warrant is tainted — based on the opposition research dossier on Trump and Russia that was paid for by Democrats — and that because the FISA warrant helped launch the FBI investigation into Trump and Russia, the whole investigation is tainted.
Democrats, however, say that the FISA warrant on Page was justified because of his contacts with Russia, and they argue that the FBI and Justice Department followed proper procedure in seeking and getting the Foreign Intelligence Surveillance Court to approve the warrant.
In a statement Saturday, the top Democrat on the House Intelligence Committee, Rep. Adam Schiff, said the applications "underscore the legitimate concern FBI had about Page's activities as it was investigating Russia's interference."
"These documents affirm that our nation faced a profound counterintelligence threat prior to the 2016 election, and the Department of Justice and FBI took appropriate steps to investigate whether any U.S. persons were acting as an agent of a foreign power," Schiff said.
The dispute over Page's FISA warrant has been previously fought in the form of dueling memos that Nunes and Schiff issued earlier this year.
Nunes' memo, which was cited by President Donald Trump in his attacks on the Mueller investigation, alleges that the author of the dossier, ex-British intelligence agent Christopher Steele, harbored anti-Trump motivations that were not disclosed in the FISA application.
Worse, the memo alleges, the FISA court was not told that Steele's dossier was funded through a law firm by the Democratic National Committee and the Hillary Clinton campaign.
Democrats responded with their own memo, which argued that the FBI's interest in Page predated the FBI's knowledge of the Steele dossier. It also argues that it was not the dossier and the Page FISA warrant that prompted the FBI's counterintelligence investigation into Russia, but rather an earlier conversation that former Trump campaign adviser George Papadopoulos had with an Australian diplomat about alleged Russian dirt on Clinton.
The material in a FISA warrant is considered highly classified, and the Foreign Intelligence Surveillance Court proceedings are also conducted in secret.
But after Nunes issued a subpoena to gain access to the documents, he used a House procedure to make public classified materials, so long as the White House did not object.
The release of some information related to the Page FISA document in both the Republican and Democratic memos led to lawsuits from groups like Judicial Watch seeking more information from the Page FISA warrant.