The U.S. Secret Service (USSS) is investigating an agent accused of sexually assaulting a staffer working on Vice President Harris' presidential campaign.

Real Clear Politics first reported the allegations Wednesday. According to four USSS sources, the incident took place last week in Wisconsin.

According to the report, several USSS agents and Harris campaign staffers were in Green Bay to work on security measures for an upcoming rally. The campaign event in Green Bay ended up not taking place, and the campaign switched the rally location to Atlanta, Georgia, after holding a rally in Madison, Wisconsin, on Friday.

The staffers and agents later drank at a local restaurant after finishing up their work for the day. They eventually moved over to the victim's hotel room – where the alleged assault took place.

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A Harris campaign staffer accused a Secret Service agent of sexual assault last week, reports say. (Getty Images / iStock)

The suspect, who was intoxicated at the time, had forced himself on the victim and began groping her, the report claims. The incident was witnessed by other people.

The suspect was reportedly so drunk that his coworkers kicked him out of their hotel room, and he fell asleep in the hallway.

A Secret Service spokesperson confirmed an investigation to Fox News Digital, but did not disclose if it involved a Harris staffer.

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Vice President Harris speaks during a campaign event in Madison, Wis., on Friday. (Alex Wroblewski/Bloomberg via Getty Images)

"The U.S. Secret Service Office of Professional Responsibility is investigating a misconduct allegation involving an employee," the spokesperson said. "The Secret Service holds its personnel to the highest standards."

"The employee has been placed on administrative leave pending the outcome of the investigation."

Vice President Harris waves during a campaign event in Madison, Wis., on Friday.  (Alex Wroblewski/Bloomberg via Getty Images)

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Harris’ office said in a statement that "we have zero tolerance for sexual misconduct," and that the office takes "safety of staff seriously," according to the Associated Press.

Fox News Digital reached out to the Harris campaign for comment.