The unidentified woman alleges that Xavier Morales assaulted her on March 31, after they came back from a party at a local restaurant. When she rebuffed his advances, he grabbed her.
The incident occurred near the agency headquarters in downtown Washington, D.C.
Morales did not respond to request from Reuters for comments. Without providing any names, an agency spokesman confirmed in an email that an incident had been reported to investigators, and that a supervisor had been placed on administrative leave and their security clearance suspended.
The incident is being investigated by both local police and the Department of Homeland Security’s Office of the Inspector General. The Secret Service is part of the Department of Homeland Security.
"These allegations as reported are very disturbing. Any threats or violence that endangers our employees in the workplace is unacceptable and will not be tolerated," Secret Service Director Joseph Clancy said in a statement released on Tuesday evening.
The agency that protects the president and his family has suffered a series of scandals in recent years, including allegations that some agents traveling with President Obama in Colombia hired prostitutes and partied with them at a Colombian hotel.
The Secret Service is also accused of lax security after several people have successfully scaled the White House fence, with one person entering the White House itself and managing to get through several rooms before they were finally stopped. And recently two agents suspected of being under the influence of alcohol struck a barricade in the front of the White House and drove through an ongoing investigation into a bomb threat. A supervisor was reprimanded in that incident after he told the agents to go home and sleep it off, without reporting it until days later.