WASHINGTON — A senior Obama administration political appointee and longtime aide to Homeland Security Secretary Janet Napolitano resigned Saturday amid allegations of inappropriate sexual behavior lodged by at least three Immigration and Customs Enforcement employees.

Suzanne Barr, chief of staff to ICE Director John Morton, said in her resignation letter that the allegations against her are “unfounded.” But she said she was stepping down anyway to end distractions within the agency. ICE, a division of the Homeland Security Department, confirmed Barr had resigned. The Associated Press obtained a copy of Barr’s letter.

Barr is accused of sexually inappropriate behavior toward employees. The complaints are related to a sexual discrimination and retaliation lawsuit filed by a senior ICE agent in May.

In her letter to Morton, Barr said she has been the subject of “unfounded allegations designed to destroy my reputation” and is resigning “with great regret.”

Barr wrote, “I feel it is incumbent upon me to take every step necessary to prevent further harm to the agency and to prevent this from further distracting from our critical work.”

Barr went on leave last month after the New York Post reported on the lawsuit filed by James T. Hayes Jr., ICE’s special agent in charge in New York. Additional employees came forward with their allegations around the same time.

In one complaint, Barr is accused of telling a male subordinate he was “sexy” and asking a personal question about his anatomy during an office party. In a separate complaint, she is accused of offering to perform a sex act with a male subordinate during a business trip in Bogota, Colombia. She’s also accused of calling a male subordinate from her hotel room and offering to perform a sex act. The names of two accusers were censored in affidavits reviewed by AP.

Homeland Security’s office of professional responsibility and inspector general have been investigating the allegations.

Prior to the lawsuit, there were no complaints about Barr, according to a homeland security official who spoke to the AP on condition of anonymity because he was not authorized to speak publicly about the matter.

In the lawsuit, Hayes described a “frat house” atmosphere at ICE designed to humiliate male employees under Barr’s leadership. Hayes, who was transferred to New York from ICE headquarters in Washington, is asking for more than $4 million that, among other things, would cover compensation he believes he is owed for relocation expenses and financial losses associated with his transfer.