A female aide to Sen. Kirsten Gillibrand, D-N.Y., resigned last year in protest over the senator's office's handling of her sexual harassment complaint, Politico reported Monday.

The aide also criticized Gillibrand — a champion of the #MeToo movement who has made combating sexual misconduct a cornerstone of her 2020 presidential campaign — for not abiding by her own public standards.

The staffer alleged that last July one of Gillibrand's longtime aides, Abbas Malik, who is a decade older than her and married, made unwelcome advances toward her after Gillibrand told him he would soon become her superior. The aide also said Malik regularly made crude and misogynistic remarks in the office.

Malik did not respond to Politico's requests for comment. The woman was granted anonymity by Politico because she feared retaliation and damage to her employment prospects, and NBC has been unable to verify her allegations.

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Gillibrand said Monday in a statement about her office's handling of the allegations: "These are challenges that affect all of our nation’s workplaces, including mine, and the question is whether or not they are taken seriously. As I have long said, when allegations are made in the workplace, we must believe women so that serious investigations can actually take place, we can learn the facts, and there can be appropriate accountability. That’s exactly what happened at every step of this case last year. I told her that we loved her at the time and the same is true today."

The woman wrote Gillibrand and top staffers a letter on her last day working for the senator criticizing the office's handling of her complaint and explaining her reasons for leaving.

"I have offered my resignation because of how poorly the investigation and post-investigation was handled," she wrote, according to Politico, which obtained a copy of the letter. "I trusted and leaned on this statement that you made: 'You need to draw a line in the sand and say none of it is O.K. None of it is acceptable.' Your office chose to go against your public belief that women shouldn’t accept sexual harassment in any form and portrayed my experience as a misinterpretation instead of what it actually was: harassment and ultimately, intimidation."

Gillibrand's office said it didn't respond to the letter because it determined that “engaging again on an already settled personnel matter was not the appropriate course of action,” Politico reported. The office also told the news organization that the letter came after the woman had given three weeks’ notice, "contained clear inaccuracies and was a major departure from the sentiments she shared with senior staff in her final days in the office."

Malik kept his job after the aide left. But when Politico presented the office with its own finding of additional allegations of inappropriate workplace conduct by him, including allegedly making a rape "joke" to a female co-worker, Gillibrand's staff opened a new probe into the top aide and dismissed him last week.

In a statement about the office's handling of the allegations, Gillibrand's communications director, Whitney Mitchell Brennan, said that "at every step of the process, immediate action was taken by the office."

"A full and thorough investigation into the evidence revealed employee misconduct that, while inappropriate, did not meet the standard for sexual harassment," Brennan said in the statement. "However, because the office did find unprofessional behavior that violated office policy, including derogatory comments, the office took strong disciplinary action against the employee in question and he was given a final warning."

After learning of additional allegations as a result of Politico's reporting, Brennan said the office "immediately began another investigation and interviewed relevant witnesses," which led to Malik's termination.