Boston — Massachusetts U.S. Attorney Rachael Rollins will resign following a monthslong investigation by the Justice Department's inspector general into her appearance at a political fundraiser and other potential ethics issues, her attorney said Tuesday.

The Justice Department's watchdog has yet to release its report detailing the findings of its investigation, but an attorney for Rollins told The Associated Press that she will be submitting a letter of resignation to President Joe Biden by close of business Friday.

The resignation of a U.S. attorney amid ethics concerns is an exceedingly rare phenomenon and is especially notable for a Justice Department that under Attorney General Merrick Garland has sought to restore a sense of normalcy and good governance following the turbulent four years of the Trump administration.

Rollins' attorney said she has been “profoundly honored” to have served as U.S. attorney and proud of her office's work but “understands that her presence has become a distraction.” Attorney Michael Bromwich — a former Justice Department inspector general — said Rollins will make herself available to answer questions “after the dust settles and she resigns.”

"The work of the office and the Department of Justice is far too important to be overshadowed by anything else,” Bromwich said.

The Justice Department didn't immediately comment Tuesday. The inspector general's office declined to comment.

Rollins was a controversial pick to be Massachusetts’ top federal law enforcer and twice needed Vice President Kamala Harris to break a tie for her nomination to move forward in the Senate amid fierce opposition from Republicans, who painted her as a radical.

Before taking the high-profile U.S. attorney job, she was the top prosecutor for Suffolk County, which includes Boston. In her role there, she sparred with Boston’s largest police union and pushed ambitious criminal justice changes, most notably a policy not to prosecute certain low-level crimes such as shoplifting.

She was the first woman of color to serve as a district attorney in Massachusetts and the first Black woman to become U.S. attorney for the state.

Massachusetts Democratic Sens. Ed Markey and Elizabeth Warren, who had pushed for Rollins to be nominated to the post, said in a joint statement that they will respect her decision to step down.

“Rachael Rollins has for years dedicated herself to the people of Massachusetts and equal justice under the law," they said.

The Associated Press was the first to report in November that the inspector general’s office had opened an investigation into Rollins over her appearance last year at a home in Andover, Massachusetts, for a Democratic National Committee fundraiser featuring first lady Jill Biden. That was according to two people briefed on the investigation, who spoke on the condition of anonymity because they were not authorized to discuss the probe.

The inspector general’s office generally investigates allegations of fraud, abuse or violation of other Justice Department policies.

People familiar with the investigation told the AP at the time that the probe had expanded into other areas, including Rollins’ use of her personal cellphone to conduct Justice Department business and a trip she took to California that was paid for by an outside group.

Rollins said in a July tweet that she “had approval” to meet the first lady and left the event early to speak at two community events. One person familiar with discussions before that event told the AP that Rollins was only given limited permission to meet Jill Biden outside the home.

The U.S. Office of Special Counsel, another federal watchdog agency, has also been investigating whether Rollins’ attendance at the fundraiser violated the Hatch Act, a law that limits political activity by government workers. The status of that investigation is unclear.

The inspector general’s office copied the phone contents of some employees in Rollins’ office as part of their probe into her possible use of her personal phone for Justice Department business, one person familiar with the matter told the AP last year.

Investigators also examined a trip Rollins took to California that was paid for by an outside group, even though Justice Department employees are not supposed to accept payments for travel. The trip was for CAA Amplify, the annual gathering of entertainment, business and political figures run by one of Hollywood’s leading talent agencies, the Creative Artists Agency.

Republican Sen. Tom Cotton of Arkansas, a fierce critic of Rollins who had sought to block her confirmation, had urged the inspector general last year to investigate whether the U.S. attorney’s actions violated the Hatch Act.

Cotton said in a letter to Inspector General Michael Horowitz earlier this month that a “whistleblower” recently alleged that Rollins had been “removing significant numbers of documents” from the U.S. attorney’s office and “continued removing these documents even after being instructed to stop by the Department of Justice leadership.”

Rollins' attorney called the allegation “complete nonsense," adding that Cotton's time "would be better spent learning about the realities of running a law enforcement agency and fighting crime in our major cities.”

Cotton said in a statement Tuesday that he had “warned Democratic senators that Rachael Rollins wasn’t only a pro-criminal ideologue, but also had a history of poor judgment and ethical lapses.”

Tucker reported from Washington. Associated Press reporters Steve LeBlanc in Boston and Lindsay Whitehurst in Washington contributed.