(CNN) – An FBI official is under criminal investigation after allegedly altering a document related to surveillance of a Trump campaign adviser in 2016, according to several sources briefed on the matter.
Sources told CNN the document is related to the FBI’s effort to obtain FISA warrants on former Trump campaign aide Carter Page.
How important the document was to the Page investigation is unknown, but the changes were significant enough to have shifted the document’s meaning, according to the sources.
Details about the document are expected to be part of a review conducted by Justice Department Inspector General Michael Horowitz.
Horowitz is expected to release his report on Dec. 9 and testify before the Senate Judiciary Committee two days later.
The possibility that the document was changed will likely fuel outrage from Republicans, who say the FBI committed wrongdoing in its investigation of connections between the Trump campaign and Russian election meddling.