Senate Democrats on Monday said that an F.B.I. background check on Pete Hegseth, President-elect Donald J. Trump’s pick to lead the Pentagon, omitted key details on major allegations against him, in part because it did not include interviews with critical witnesses.
One missed opportunity came when the bureau did not interview one of Mr. Hegseth’s ex-wives before its findings were presented to senators last week, according to people familiar with the bureau’s investigation.
The clamor comes on the eve of Mr. Hegseth’s confirmation hearing, and just days after officials from Mr. Trump’s transition team briefed Senator Roger Wicker of Mississippi, the panel’s top Republican, and Senator Jack Reed of Rhode Island, its top Democrat, on the F.B.I.’s background check.
“There are significant gaps and inadequacies in the report, including the failure to interview some of the key potential witnesses with personal knowledge of improprieties or abuse,” Senator Richard Blumenthal, Democrat of Connecticut and a member of the committee, said in an interview.
As a rank-and-file member of the panel, Mr. Blumenthal was not given a briefing on the report or provided with a copy of it, but was informed of its contents by someone who was given access to it.
“Quite a few of the women with significant allegations against him have not been interviewed by the F.B.I. investigators,” Senator Tammy Duckworth, Democrat of Illinois and another member of the panel, said on MSNBC on Monday evening, adding that some of those women feared for their safety and that of their children.
Mr. Hegseth was accused of sexually assaulting a woman in Monterey, Calif., in 2017, in an encounter he has insisted was consensual. No charges were brought. Mr. Hegseth later paid the woman an undisclosed amount of money as part of a confidential settlement agreement.
“My understanding is that some of them would like to be contacted by the F.B.I. investigative team, or the vetters, and they have not been talked to,” Ms. Duckworth added in the MSNBC interview.
A spokeswoman for the F.B.I. declined to comment.
Mr. Trump’s transition team commissioned the F.B.I. background check on Mr. Hegseth last month after initially floating the idea of hiring private contractors to look into the president-elect’s cabinet picks. As the client, presidential transition teams are traditionally able to set the parameters for background checks into cabinet picks, and potentially dictate which witnesses are interviewed and what questions are asked. The transition team’s directions to the F.B.I. for its investigation of Mr. Hegseth are unknown.
According to people familiar with the F.B.I.’s background check, who spoke on the condition of anonymity to discuss a sensitive document, investigators reached out to Samantha Hegseth, Mr. Hegseth’s second ex-wife. The couple were married in 2010 and divorced in 2018.
F.B.I. investigators had an initial, perfunctory conversation with her on Jan. 8, according to the people familiar with or apprised of the report. Ms. Hegseth then made multiple attempts to contact the bureau for a more substantive discussion — but her calls were not returned last week, said those with knowledge of the investigation who were not authorized to speak publicly on the matter.
The panel was informed on Jan. 9 that the investigation into Mr. Hegseth had been completed. Mr. Wicker and Mr. Reed were briefed on Jan. 10. Rank-and-file Democrats have been demanding to review the full F.B.I. document, but have not been allowed to do so.
Asked why the F.B.I. did not interview Ms. Hegseth last week, Karoline Leavitt, a spokeswoman for the Trump transition team, referred a reporter to the bureau.
The Hegseths, who share custody of three children, had a contentious divorce. She worked for Mr. Hegseth at a small nonprofit he led while he was married to his first wife, who filed for divorce, citing adultery.
In 2017, seven years after Pete and Samantha Hegseth were married, Mr. Hegseth, then an anchor on the TV program “Fox & Friends,” had a child with his producer. Ms. Hegseth filed for divorce the next month.
In 2018, before their divorce was finalized, Mr. Hegseth’s mother, Penelope Hegseth, sent her son an email condemning what she described as his abusive treatment toward women. She has since recanted her criticism of her son and defended him as a changed man who deserves to be confirmed as defense secretary.
The panel has scheduled a vote on Mr. Hegseth’s confirmation for Jan. 20, the date of Mr. Trump’s inauguration.
A committee spokesman for Mr. Wicker did not return requests for comment late Monday, and a committee spokesman for Mr. Reed declined to comment.
Devlin Barrett contributed reporting.
