Washington (CNN) The Justice Department and FBI are reviewing a draft of the long-awaited report on Foreign Intelligence Surveillance Court applications regarding the Trump campaign, the department's inspector general said Friday.

Inspector General Michael Horowitz sent a letter to four congressional committees on Friday notifying them that he had begun "finalizing our report by providing a draft of our factual findings to the Department and the FBI for classification determination and marking."

The inspector general has been investigating since early 2018 the handling of four applications that let American intelligence eavesdrop on Carter Page in 2016 and 2017 after he left the Trump campaign. The warrants, which cite the Trump-Russia dossier by ex-British spy Christopher Steele, and the investigation of them have allowed Republicans to continue speculating that the early investigation into the Trump campaign and Russia interference in the election was driven by politics.

Horowitz noted that the report contained classified material, and that once he receives the draft back from DOJ and FBI, his office would prepare the report for release, "ensuring that appropriate reviews occur for accuracy and comment purposes."

Horowitz said that his team had reviewed more than 1 million records and conducted more than 100 interviews as part of the review. CNN has previously reported that investigators this year spoke to Steele.

Read More