An investigation by District officials has uncovered signs of widespread enrollment fraud at the Duke Ellington School of the Arts, a nationally recognized incubator of theatrical talent and one of the city’s most revered public schools, according to current and former D.C. government officials with knowledge of the probe.

Scrutiny of the records of an initial sample of roughly 100 students whose families claimed D.C. residency — thus avoiding the annual tuition of more than $12,000 charged to nonresident students — found that more than half may live outside the city, two officials said.

That finding was shared in December at a meeting attended by representatives from the D.C. Office of the State Superintendent of Education — which was managing the investigation — and the office of the D.C. attorney general, the officials said.

Shortly after that, a lawyer in the state superintendent’s office told those handling the case in that office to “take your time” because of the risk of negative publicity during a mayoral election year, said the officials with knowledge of the probe. It is unclear how far the investigation has progressed since then.

About 70 of Ellington’s 566 students are on record as living outside the District, and their families pay tuition to the school system. The probe is focused not on those students but on the majority who claim to be D.C. residents.

The investigation — based on a preliminary review of public records associated with students’ parents — is not complete. The state superintendent’s office is now checking the residency of every Ellington student. But officials said the audit has identified many families whose claims of residency are highly suspicious.

After The Washington Post published a version of this report on its website Tuesday morning, Mayor Muriel E. Bowser (D) and State Superintendent of Education Hanseul Kang called a news conference about the previously undisclosed investigation. They said that it was ongoing and that they would not be able to discuss results until it was complete.

Bowser said in a later interview that she had first learned of the investigation Tuesday.

“This is an audit — and it’s become a deeper audit — that has been ordered by the Office of the State Superintendent, and we have no reason not to want to know what that information is,” Bowser said.

She said she was confident Kang had not indicated to any of her employees that the investigation should be slowed to avoid bad publicity.

“People say all kinds of crazy things, and if you have an employee who said something like that, that would obviously be inappropriate,” Bowser said. “But the superintendent did not say that or direct anybody that way.”

Kang, during a previously scheduled appearance before the D.C. Council’s Education Committee, testified Tuesday that the probe had grown out of the annual audit of student residency at all D.C. public schools and that “specific concern” about the findings at Ellington had led to an ongoing investigation after the systemwide audit was finished.

She said she had “no knowledge” of any employee directing investigators to slow down because it was election season.

“I am deeply concerned about the alleged comment,” Kang testified. “That is absolutely not acceptable, and I will be investigating further with my team.”

Council member and Education Committee chairman David Grosso (I-At Large) said in an interview that the state superintendent’s office was getting better at investigating residency but should have informed the council and the public about its Ellington findings in December.

“This is something that we are doing a better job at,” he said. “It’s just that they made a really bad decision to not come out publicly and talk about this reality.”

D.C. Attorney General Karl A. Racine (D) said in a statement that his office takes tuition fraud “very seriously because it cheats both our students and our taxpayers.”

The revelations about the investigation come on the heels of other scandals buffeting the District’s public schools, including a federal investigation of graduation rates and the abrupt resignation last week of Chancellor Antwan Wilson, who had violated the school district’s enrollment policies to secure a seat for his daughter at a sought-after high school.

It also could be a blow for Ellington, a 43-year-old magnet school in Georgetown whose self-declared mission is to offer a premier arts education to District children who lack the financial means to develop their talents elsewhere.

A high rate of residency fraud could indicate that the mission is suffering as D.C. taxpayers fund the education of children who live outside the city.

The investigation could throw the school’s community into turmoil, with dozens of families facing potential lawsuits by the attorney general’s office, which under a District law passed in 2011 can pursue monetary judgments against parents who violate the school district’s residency rules.

Rumors about residency fraud have floated around some D.C. public schools for years — particularly as the city’s heavily publicized education initiatives and modernized schools have made its campuses more attractive to suburban parents.

But Ellington holds a special appeal. The city poured approximately $170 million into a renovation project at the arts school’s campus that wrapped up last year.

The imprimatur of an Ellington diploma has helped establish the careers of alumni such as comedian Dave Chappelle, opera singer Denyce Graves and conceptual artist Hank Willis Thomas. Last year, Ellington reported that 96 percent of its students graduated within four years, one of the District’s highest high school graduation rates.

D.C. resident Deanna Anderson, whose son is applying to Ellington, was leaving the school after a family admissions interview Tuesday. She said she could understand why some families might feel driven to cheat the system. “As a parent, I would do what I have to do to get the best education for my child, so if I had to go through drastic measures to do so, then I absolutely would,” Anderson said, adding that there are few arts schools on the level of Ellington in the area.

Residency fraud to avoid school tuition can take many forms, from using a grandparent’s address to forging a lease. The scope of deception at Ellington, if substantiated, would dwarf what was previously thought to be the scale of the District’s problem: Authorities reported only nine cases in the entire public school system last year.

Those cases, when successfully pursued by the attorney general’s office, can result in hefty fees — under the District’s False Claims Act, a court can triple the fines for someone found to have deliberately tried to avoid paying money to the city.

In 2016, two married District police officers who lived in Maryland but sent their three children to highly regarded D.C. public schools for a decade were ordered by a judge to pay more than $500,000.

Ellington has an intensely competitive admissions process. Students must audition in their chosen art form, and their family is interviewed. Once admitted, they go through 15 hours a week of pre-professional arts training. The student body is 77 percent African American, 11 percent Latino and 7 percent white, according to data from the school district.

Although the school is funded and overseen by the District, it has its own board of directors and benefits from extra money raised by an affiliated nonprofit group, the Ellington Fund.

The probe at Ellington by the state superintendent’s office began in October, according to the officials with knowledge of the matter.

After an initial review of 100 students’ records showed that more than half had suspicious residency claims, the findings were shared among officials from the state superintendent’s and attorney general’s offices in December.

The state superintendent is responsible for overseeing the integrity of the school enrollment process, among other oversight functions for the District’s public and charter schools.

Since then, the probe appears to have lost steam.

Bowser, who appointed Kang in 2015, is up for reelection this fall. Despite the repeated scandals that have hit the school district over the past three months, the mayor faces no serious challengers in the June Democratic primary, which typically decides the general-election winner in the left-leaning District.

Heralded over the past decade as a national model for education reform, the D.C. school system has come under scrutiny as the result of recent scandals that have marred its image and strained parents’ trust.

A school district investigation released last month found that one-third of last year’s high school graduates should not have received diplomas, because of chronic truancy and other problems. The potential ma­nipu­la­tion of graduation rates has led to an investigation of the school system by the FBI, the U.S. Education Department and the D.C. Office of the Inspector General.

Last week, Wilson — who began work as schools chancellor just over a year ago — was forced to resign after the mayor’s office disclosed that he had evaded the rules of the District’s notoriously competitive enrollment process to transfer his daughter to Wilson High, a school in Northwest Washington that has a waiting list of more than 600 students.

Deputy Mayor for Education Jennifer Niles also resigned after she acknowledged helping to facilitate the transfer.

Emma Brown and Allyson Chiu contributed to this report.