Infighting at the United Automobile Workers burst into public view on Sunday after Shawn Fain, the union’s president, responded angrily to accusations that he had abused his position to seek special favors for his fiancée and her sister.
The accusations were made by Rich Boyer, the vice president who is vying for the union presidency. Mr. Boyer also said that Mr. Fain had made false accusations against him, including a “dereliction of duty,” after he refused to approve the favors, according to a report by a court-appointed monitor.
The Department of Justice has opened a grand jury investigation into whether Mr. Fain had abused his office, according to an email sent to union officials and lawyers whose contents were shared with The New York Times. The investigation was earlier reported by Bloomberg.
Mr. Fain did not explicitly confirm the existence of a grand jury investigation, but said that he was the victim of “bogus allegations” intended to sway the upcoming elections.
“This is what happens when you go against corporate America and their allies, and I’m not going to be intimidated or harassed out of serving our membership,” Mr. Fain said.
A spokesman for the U.A.W. said the union was not the focus of a grand jury investigation. The Department of Justice did not immediately respond to requests for comment on Sunday.
Mr. Fain and Mr. Boyer are leading rival slates of candidates in elections for top positions at the U.A.W., one of America’s most powerful unions, with about 400,000 active members. Mail-in balloting is scheduled to begin late next month.
In 2024, Mr. Fain sought to curtail Mr. Boyer’s role overseeing relations with Stellantis, the maker of Jeep and Chrysler vehicles, accusing him of undermining the union position in negotiations with the company, according to a report last month by Neil M. Barofsky, a court-appointed monitor. Mr. Barofsky is overseeing the union’s compliance with an agreement it made with the federal authorities in 2021 after a previous corruption scandal.
Mr. Fain contended in 2024 that Mr. Boyer had made concessions in negotiations with Stellantis without authorization and did not try hard enough to enforce a promise by the carmaker to reopen a factory in Belvidere, Ill.
According to Mr. Barofsky’s report, Mr. Fain’s effort to reduce Mr. Boyer’s authority was in retaliation for Mr. Boyer’s refusal to intervene in a workers’ compensation claim by the sister of Mr. Fain’s fiancée and Mr. Boyer’s refusal to approve a bonus that would have benefited the fiancée.
“Fain’s actions were improper and fit into what has become a recurring pattern of retaliation,” the report said.
Mr. Barofsky has received a subpoena from the Justice Department, according to the email sent to union officials and lawyers involved in the case. A spokeswoman for Mr. Barofsky declined to comment.
The dispute casts a shadow over the union as it tries to expand its influence into auto factories in Southern states operated by automakers like Mercedes-Benz, Toyota and Hyundai that have been difficult to organize.
The union is also still recovering from a scandal that led to prison sentences for numerous high-ranking union officials, including two former presidents, on charges including bribery and embezzlement.
Mr. Fain has had some notable victories since becoming president in 2023. That year, the U.A.W. won the most generous pay raises in years from Ford Motor, General Motors and Stellantis.
The Justice Department under President Trump has been aggressively ramping up its efforts to use the powers of federal law enforcement to scrutinize prominent left-leaning public figures and organizations, including Gov. Gavin Newsom of California; the Southern Poverty Law Center, a civil rights group; and ActBlue, a major Democratic fund-raising group.
Mr. Fain has called Mr. Trump a “scab,” though he has also applauded the president’s tariffs on imported autos and auto parts.
