FILE PHOTO: U.S. Supreme Court nominee judge Brett Kavanaugh testifies during his Senate Judiciary Committee confirmation hearing on Capitol Hill in Washington, U.S., September 5, 2018. REUTERS/Chris Wattie/File Photo

WASHINGTON (Reuters) - The U.S. Senate Judiciary Committee is looking into at least one additional allegation of misconduct against Supreme Court nominee Brett Kavanaugh, NBC News reported on Wednesday.

According to an anonymous complaint in a letter sent to Republican Senator Cory Gardner, Kavanaugh physically assaulted a woman he socialized with in the Washington area in 1998 while he was inebriated, NBC News said, citing the letter and multiple people familiar with the process.

Kavanaugh denied the allegation in the letter during a call on Tuesday with committee staff, NBC News said, citing unnamed sources.