Washington (CNN) The Senate Judiciary Committee has referred an individual who made "materially false statements" alleging misconduct by Supreme Court nominee Brett Kavanaugh to the FBI and Justice Department for a criminal investigation.

"Such acts are not only unfair; they are potentially illegal," committee Chairman Chuck Grassley wrote in a letter Saturday to Attorney General Jeff Sessions and FBI Director Chris Wray.

Grassley wants the FBI and DOJ to investigate whether the individual potentially obstructed the committee's nomination process of Kavanaugh by providing fraudulent information to committee investigators.

"It is illegal to make materially false, fictitious, or fraudulent statements to Congressional investigators. It is illegal to obstruct Committee investigation," the Iowa Republican wrote.

The office of Rhode Island Sen. Sheldon Whitehouse, a Democrat who sits on the Judiciary Committee, received a call on Monday concerning an allegation -- now found to be false -- of a 1985 incident in Newport where a woman was sexually assaulted on a boat by two heavily inebriated men she referred to as "Brett and Mark."

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