An ex-sister-in-law of Pete Hegseth’s submitted a sworn statement to senators on Tuesday that accused Mr. Hegseth, President Trump’s nominee for secretary of defense, of being so “abusive” toward his second wife that she once hid in a closet from him and had a safe word to call for help if she needed to get away from him.
In a Capitol Hill office on Tuesday afternoon, senators were reviewing the affidavit, from Danielle Diettrich Hegseth, the former wife of Mr. Hegseth’s brother, which describes “erratic and aggressive” behavior by Mr. Hegseth that caused his second wife to fear for her safety. According to a copy obtained by The New York Times, it also asserts that he frequently drank to excess both in public and private, including on one occasion she witnessed when he was wearing his military uniform.
The allegations, which Mr. Hegseth denied through his lawyer, surfaced as Republicans were working to speed him to confirmation, and could imperil that push. About a half-dozen Republicans who have learned of the accusations in recent days have privately raised serious concerns about them, according to people familiar with the conversations, suggesting that the new information could potentially sap the necessary support for his approval by the Senate.
In her affidavit, reported earlier by NBC News, Danielle Hegseth said she had spoken with the F.B.I. about Mr. Hegseth and had come forward to Congress in the hopes that her account would persuade enough Republicans to block him. She said she was submitting her account at the request of Senator Jack Reed of Rhode Island, the top Democrat on the Armed Services Committee.
“I have been assured that making this public statement will ensure that certain senators who are still on the fence will vote against Hegseth’s confirmation,” she wrote.
Mr. Reed said the account describes behavior that is disqualifying, and “confirms my fears” that the F.B.I. background check on Mr. Hegseth had been incomplete.
“The alleged pattern of abuse and misconduct by Mr. Hegseth is disturbing,” he said. “This behavior would disqualify any service member from holding any leadership position in the military, much less being confirmed as the secretary of defense.”
In the affidavit, sent Tuesday to the Armed Services panel, Danielle Hegseth wrote that Mr. Hegseth’s second wife, Samantha Hegseth, on one occasion between 2014 and 2016 “hid in her closet from Hegseth because she feared for her personal safety.”
She also said that Samantha Hegseth had given her a code word, shared with Danielle and another person, that she would use if she needed help. According to the sworn statement, Samantha Hegseth texted Danielle Hegseth the code word once in either 2015 or 2016, and Danielle contacted the other person to put the plan into motion.
Danielle Hegseth said that she “did not personally witness physical or sexual abuse by Hegseth,” but that she saw what she described as “erratic and aggressive behavior” by him over many years. She also recounted a number of instances in 2008 or 2009, as well as around 2013, in which she had witnessed Mr. Hegseth being intoxicated to the point of passing out.
The new allegations are strikingly similar to a raft of accusations that had already surfaced since Mr. Trump chose him to lead the Pentagon. Mr. Hegseth has adamantly denied the allegations and dismissed them as politically motivated smears from anonymous sources.
Tim Parlatore, a lawyer for Mr. Hegseth, denied Danielle Hegseth’s charges in a statement.
“Sam has never alleged that there was any abuse, she signed court documents acknowledging that there was no abuse and recently reaffirmed the same during her F.B.I. interview,” Mr. Parlatore said, accusing Danielle Hegseth of being “an anti-Trump far-left Democrat” who “had an ax to grind against the entire Hegseth family.”
Samantha Hegseth shares custody of three children with Mr. Hegseth. She was interviewed by the F.B.I. as part of her ex-husband’s background check. In that interview, she told investigators that Mr. Hegseth abused and continues to abuse alcohol, according to a person with knowledge of the findings. The F.B.I. had no comment.
Ms. Hegseth could not be reached for comment on Tuesday. In a statement to NBC News on Monday, before Danielle Hegseth filed her detailed affidavit, she said “there was no physical abuse in my marriage” and that she would not speak further about her marriage.
In a 2021 order, dealing with the appointment of a parenting coordinator, a Minnesota family court judge said neither of the Hegseths claimed to be a victim of domestic abuse. The judge also said that there was no determination by the court that there was probable cause to believe that one parent “has been physically abused or threatened with physical abuse by the other parent.”
It is still unclear whether the new allegations will sway any Republicans to oppose Mr. Hegseth, whose nomination was approved behind closed doors on Monday along party lines. He can afford to lose only three G.O.P. votes given that Democrats have signaled they are ready to vote against him en masse. For now, it is the sister-in-law’s word against Mr. Hegseth’s, since a corroborating witness — who would likely have to be Samantha Hegseth — has not yet stepped forward.
Mr. Hegseth’s nomination had already been dogged by an allegation of sexual assault, and accusations of public intoxication and financial mismanagement. He paid a settlement to the woman who accused him of raping her in 2017. He denied the woman’s allegations and was never charged with a crime.
Danielle Hegseth’s sworn statement is the first time that a former member of Mr. Hegseth’s family circle has publicly described personal conduct they argue renders him unfit to lead the Pentagon. Mr. Hegseth’s mother said in a 2018 email that he had mistreated women for years, but has since disavowed those sentiments.
Samantha Hegseth treated Danielle Hegseth as a confidante, according to people familiar with their relationship. She was married to Pete Hegseth’s brother Nathaniel from 2011 to 2019; Samantha and Pete Hegseth were married from 2010 to 2018.
During his confirmation hearing, Mr. Hegseth emphatically denied having physically harmed any of his ex-wives.
“Did you ever engage in any acts of physical violence against any of your wives?” Senator Tim Kaine, Democrat of Virginia, asked Mr. Hegseth during his confirmation hearing last week.
“Senator, absolutely not,” Mr. Hegseth replied. When then asked twice if physical violence toward a spouse ought to disqualify a nominee, he demurred, again insisting on his innocence and calling Mr. Kaine’s question a hypothetical.
Mr. Hegseth described the other allegations as “anonymous smears.” Though he never admitted to specific ill behavior, he spoke emphatically about being a changed man.
“I’m not a perfect person, but redemption is real,” he told senators. He also credited his current wife, Jennifer Rauchet, with having “changed my life.”
Many of the allegations in Danielle Hegseth’s affidavit detailed episodes of Mr. Hegseth’s apparent drunkenness, and in some, she said, he made racial statements she found offensive.
“He drunkenly yelled in my face one night in 2009,” she wrote, recalling that Mr. Hegseth had become upset after she walked out of a room when he was telling a story “with a racial slant that bothered me.”
“He was very aggressive, in my face, dressed in his military uniform,” she added.
In 2013, she said, Mr. Hegseth drank so much at a family dinner at a Minneapolis restaurant that afterward an Uber driver had to pull over on an interstate highway so he could vomit. At another bar that same year, she said, Mr. Hegseth danced drunk with a glass of gin and tonic in each hand, dropped the glasses on the dance floor and had to be dragged out of the bar.
She said that she recounted to the F.B.I. another episode that occurred in 2009, when she was still married to Mr. Hegseth’s brother, but said she did not have firsthand knowledge of it. She said she was told that after a drill with the National Guard, Mr. Hegseth was found at a nearby strip club, drunk and in uniform, getting lap dances.
She said the person who told her about the episode said that was a violation of military rules. That person’s name was redacted in the affidavit obtained by The Times.
A spokesman for Senator Roger Wicker, the Mississippi Republican who chairs the Armed Services Committee, did not immediately respond to a request for comment Tuesday. On Monday, before the affidavit was sent to the committee, Mr. Wicker said in an interview that he was aware that new allegations were being raised, and that “if they were substantiated and taken seriously, we’d look at them.”
A spokesman for Senator John Thune, Republican of South Dakota and the majority leader, also did not immediately respond to a request for comment.
Democrats who reviewed Danielle Hegseth’s affidavit on Tuesday said they were stunned by the litany of allegations. Several of them said that the F.B.I. had not done a thorough enough job.
“It’s clear that the F.B.I. has not followed up on the leads that it’s been given and has rushed through a report that is incomplete,” Senator Elizabeth Warren, Democrat of Massachusetts, told reporters Tuesday.
The F.B.I. said a week ago that background checks focus on character and conduct. Once the bureau “has taken the requested investigative steps,” the statement said, its report is given to the transition team or the White House for officials to use as they see fit.
As the clients, presidential transition teams are often able to set the terms of such investigations, potentially including which witnesses were interviewed and which questions were asked. It is not clear what the transition team’s directions to the F.B.I. were.
Maya C. Miller and Devlin Barrett contributed reporting. Kitty Bennett and Julie Tate contributed research.