WASHINGTON - A Republican senator says edits to a draft FBI statement on the Hillary Clinton email investigation appear to have watered down the significance of the bureau's findings.

Sen. Ron Johnson of Wisconsin, the chairman of the Senate Homeland Security Committee, said Thursday he had obtained from the FBI a draft statement that then-Director James Comey produced in May 2016 in anticipation of closing out the Clinton email case. The document shows line-by-line edits.

Though the FBI had not yet interviewed Clinton about her use of a private email server, officials had already determined that criminal charges were probably not warranted.

In a letter to the FBI, Johnson said edits to Comey's original remarks "appear to change the tone and substance" in ways that lessen the seriousness of the case.

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Johnson highlights the changing of the wording from "grossly negligent" to "extremely careless." CBS News has reported the word change was led by Peter Strzok, the senior FBI agent who sent texts disparaging of Donald Trump.