Administrators and parents at Duke Ellington School of the Arts say a significant share of families accused of residency fraud have been cleared of wrongdoing — an assertion that appears to undermine a high-profile investigation that rocked the acclaimed public arts school in the District.

In May, a citywide investigation alleged that 164 Ellington students — nearly 30 percent of the student body — lived outside the District and unlawfully attended the school without paying the tuition required of suburbanites. An additional 56 students were flagged for less clear-cut residency problems and told to provide more documents to verify their residency.

But families and top officials at Ellington say they have tracked at least 90 accused students whose cases have been dismissed after the city determined they reside in the District.

The Washington Post reviewed letters the city sent to 25 families dismissing their cases. Nearly 70 other families sent emails to a group of Ellington parents informing them that their cases had been cleared. Parents from “I Am Ellington” — a group formed to help accused families navigate the appeals process — allowed The Post to review each of these emails.

Ellington’s chief executive, Tia Powell Harris, and principal, ­Sandi Logan, said they have also tried to track the outcomes of students’ cases and determined that more than 90 students have been cleared of wrongdoing.

“I would never say that there are parents who haven’t misrepresented their residency,” Powell Harris said. “But I think the extent to which that happens has been blown up.”

In an interview Saturday, Mayor Muriel E. Bowser (D) said she did not know the precise number of cases that had been dismissed but was aware that some families had provided additional information to prove their residency.

“There was always an expectation that some people will have come forward to supply information to prove residency,” she said. “If there is a big number, we would want to know why it did not come forward earlier in the process.”

When the Office of the State Superintendent of Education — the agency that conducted the investigation — determines that a family has committed residency fraud, it refers the case to the attorney general. The attorney general’s office then decides whether it will pursue the case in court. Families can be fined tuition costs — which run about $12,000 a year for students who do not live in the District — plus steep penalties.

“When we find evidence of tuition fraud, we will take action to hold individuals accountable for breaking D.C. law,” said David Mayorga, a spokesman for D.C. Attorney General Karl A. Racine. “On this particular group of cases, we are coordinating with [the superintendent’s office] to ensure we do not duplicate efforts.”

City officials said in May that they would be investigating how much Ellington administrators knew about the alleged deceptive enrollment practices.

Established in 1974 with a mission of providing a free, first-class arts education to children in the nation’s capital, the school in Georgetown has a list of celebrity alumni that includes comedian Dave Chappelle. The city recently poured more than $170 million into renovating the Ellington campus, a project that drew criticism after it went $100 million over budget.

The findings of the enrollment investigation suggested those investments were benefiting a significant number of students who lived in Maryland and Virginia.

Kia Harris’s son attends Ellington. She said she was shocked when she learned in the spring that she was suspected of committing fraud to send him there. Harris said she moved to Washington from Maryland when her son was in middle school because she thought the education options in the city were better.

But, according to Harris, investigators initially said she lived in Maryland based on a 2012 utility bill she paid while she was still living in that state. Harris said investigators also referenced her son’s father, but she said he has never been involved in her child’s life.

According to Harris, the city cleared her case in August, but she said it wasn’t really a relief.

“D.C. is so expensive. As a single mother trying to give my kid a better cultural and education experience to have this happen when I struggled to give him this experience, I was furious,” Harris said. “It’ll take me a while to trust D.C. Public Schools again.”

Maria Blaeuer is director of programs and outreach at Advocates for Justice and Education, a D.C. education advocacy organization that has worked with about 20 Ellington families accused of residency fraud. She said nearly half of the cases she handled have been dismissed.

Blaeuer said many of the families earlier lived in Maryland and fell behind on their mortgages after the Great Recession. They moved in with parents who have homes in the District, although they never signed formal leases. Some rented their Maryland homes to friends and family, formally or informally.

“Families’ lives are complicated, but that doesn’t mean they don’t have a right to attend school,” Blaeuer said. “We’ve seen families that may lose their cases, but it’s not because they are committing fraud, it’s because the laws are black and white, and their lives are not.”

Bowser said she frequently hears from constituents that their children’s schools are filled with Maryland residents, and it’s the city’s job to investigate these claims and ensure that taxpayer-funded schools are benefiting D.C. residents.

According to the May report on Ellington, the investigation into the school began during the state superintendent’s annual enrollment audit. When the agency visited the school, employees saw multiple sets of files for the same students and files that claimed students lived in the district despite supporting documentation that showed they lived in the suburbs.

“If I had a dollar for every time someone told me that there is a line of cars with Maryland license plates outside of their child’s school, I would be rich,” she said.

While the parents behind I Am Ellington did not disclose the identities of the families, the emails they shared with The Post showed that many of the families implicated in the investigation had recently moved or had complicated custodial situations.

Lucinda Woodlands, who lives in the Hillcrest neighborhood of Southeast Washington, said she has had legal custody of her granddaughter since she was a baby. She said her granddaughter has attended D.C. public schools since preschool, and Woodlands still does not understand why she was accused of residency fraud in the spring.

She said she spent hours collecting documents and fighting the charges in government offices before her case was cleared.

“I was just so angry about the whole situation,” Woodlands said. “It was just so ridiculous.”