The Secret Service is investigating one of its agents after an incident involving someone in Democratic Vice President Kamala Harris' office, her office said in a statement on Wednesday.

A U.S. Secret Service (USSS) spokesperson said separately that the employee was placed on administrative leave pending the outcome of the investigation into "a misconduct allegation involving an employee," without providing further details.

Harris' office has "zero tolerance for sexual misconduct," its statement said. Senior officials "were alerted by the USSS about an incident involving an agent and informed that USSS initiated an investigation," it read.

Neither the Secret Service agent nor the person in Harris' office were named in the statement by Harris' office. The office said it would not provide further information.

A Secret Service agent allegedly forced himself onto a Harris staffer in a hotel room in Wisconsin this week, Real Clear Politics reported, as the group scouted future campaign stops.

Harris faces Republican former President Donald Trump in what polls show to be a tight race for the Nov. 5 U.S. elections.

The Secret Service, which protects U.S. political leaders and their families, has been under scrutiny in recent weeks over the security of Trump, who survived an assassination attempt on July 13 during a rally in Pennsylvania.

The agency's former boss resigned in the aftermath and a probe found lack of diligence ahead of that shooting.