Nearly two years before election fraud allegations roiled a North Carolina congressional race this fall, state election officials warned prosecutors they had evidence of efforts to manipulate the absentee ballot vote in rural Bladen County and sought their action, new documents and interviews show.

But frustrated state officials said their alerts about what occurred in the 2016 election — including a formal referral letter sent to the U.S. attorney in January 2017 and later meetings with state and federal investigators — yielded little movement by the local district attorney or the U.S. attorney’s office to probe the allegations.

There were “several calls and in-person meetings between our investigators and federal agents working with the U.S. attorney’s office,” State Board of Election’s general counsel Josh Lawson told The Washington Post on Friday. But there was “no indication of active work by them.”

The revelation that state election officials had raised multiple alarms with law enforcement agencies raises fresh questions about whether prosecutors adequately scrutinized the allegations — and whether they could have headed off similar activities that upended this year’s race in North Carolina’s 9th Congressional District between Republican Mark Harris and Democrat Dan McCready.

Harris defeated McCready by just 905 votes in November, but the state board declined to certify the results amid allegations that illegal tampering with absentee ballots may have tainted the outcome.

At the center of the controversy is a Bladen County political operative named Leslie McCrae Dowless, who worked for the Harris campaign this year. His alleged role in ballot tampering in 2016 was a key piece of the information that state officials relayed to prosecutors, according to documents and people familiar with the case.

Dowless has declined repeated requests for interviews. His attorney, Cynthia Adams Singletary, told Raleigh’s News & Observer in a statement that Dowless “has not violated any state or federal campaign laws and current ongoing investigations will prove the same.”

The lack of action by prosecutors has angered local residents who said their complaints about Dowless’s activities were not pursued.

Brenda Register, a resident of Elizabethtown in Bladen County, said she hand-delivered a letter to local elections officials in 2016 telling them that a woman who claimed to be from the county elections board had come to her door and said she was collecting ballots. State investigators later discovered that the woman worked for Dowless, according to a state election board report released this week.

“I don’t have any faith in our county elections, because they’ve allowed so much to go on and never did anything about it,” Register said in a telephone interview. “It’s as if the ones who control the politics want him in there. . . . Whoever was in line to do this, whoever is supposed to be following up on crooked elections, is not doing their job.”

Representatives for Robert Higdon, the U.S. attorney of the Eastern District of North Carolina, have declined repeated requests for information about what actions the office has taken. On Friday, spokeswoman Leslie Hiatt said in an email that “our office has no comment.”

Bladen County District Attorney Jon David, a Republican, recused himself from the investigation in January, citing a conflict because Dowless had worked for one of his prior political opponents.

David said in a statement that his office “has been persistent in ensuring” that the state election board “would fully investigate this matter and that it received the appropriate attention from investigators.”

Republican leaders in North Carolina have accused the election board itself of not adequately investigating past allegations of fraud in Bladen County. In response, the board published a 278-page report it had prepared earlier this year for local and federal prosecutors.

“The agency investigated vigorously in support of future action by law enforcement to avoid a repeat of alleged misconduct,” Lawson said.

The state election board’s investigation dates to fall 2016, when the board received complaints from Register and two other voters alleging improper handling of absentee ballots, according to the report. Register’s son was running for a local seat against a woman who had hired Dowless that year.

Interviews with those voters, the board said, suggested that Dowless had hired people to collect mail-in ballots and “hand-carry the ballots to Dowless in order to be paid.”

Under North Carolina law, only an individual voter or a designated close relative can mail an absentee ballots.

Two Dowless employees, Caitlyn Croom and Matthew Mathis, told state investigators that Dowless told them he would give them half of their wages when they delivered the absentee ballot request forms and the rest when they gave him the ballots, according to the report.

The report also said Dowless tried to obstruct the board’s investigation by warning Croom and Mathis and coaching them about what to say if contacted. Neither could be reached for comment.

Beginning in December 2016, election board officials corresponded extensively with the office of the Bladen County district attorney about their investigation, internal correspondence shows.

The district attorney’s office expressed little interest in Dowless, according to people familiar with the situation and emails between David’s office and state election officials over several months in 2017.

Instead, the district attorney’s office sent multiple messages inquiring about a separate complaint brought by Dowless against the Bladen County Improvement Association, an advocacy group for the African American community, records show.

Dowless had accused the group of “a massive scheme to run an absentee ballot mill involving hundreds of ballots” on behalf of a write-in candidate challenging Dowless’s reelection as a supervisor of the county’s Soil and Water Conservation District, according to his claim.

After investigating, the election board found no evidence that ballots had been improperly collected by the Bladen County Improvement Association and dismissed the complaint, according to its report.

Bladen County Assistant District Attorney Quintin McGee said Friday in an email that the office thought “both entities should be prosecuted” because it appeared both had violated the law.

David said in a separate statement that his office “was steadfastly committed to ensuring that the 2016 election fraud allegations were thoroughly investigated.”

He said he recused himself once he realized that he had a potential conflict of interest and referred the case to Lorrin Freeman, the Wake County district attorney. who is based in Raleigh. Freeman has said her office is examining Dowless’s activities and whether campaigns that paid him — including Harris’s — knew of improper balloting methods.

The election board was also pressing federal prosecutors to scrutinize complaints about the 2016 election.

In January 2017, the state election board’s executive director, Kim Strach, sent a letter to then-U.S. Attorney John Bruce, stating that the agency’s investigation indicated “that individuals and potentially groups of individuals engaged in efforts to manipulate election results through the absentee ballot process.”

Strach warned that such activities “will likely continue for future elections” if not addressed.

It is unclear what action, if any, federal prosecutors took.

Bruce, a career prosecutor who served as the acting U.S. attorney for less than two years, was replaced in October 2017 by Higdon, an appointee of President Trump’s.

Bruce now works as a deputy counsel supervising investigations for the State Board of Elections. Through a spokesman, Bruce declined to comment on the 2017 referral from the state board, citing Department of Justice confidentiality rules.

Bruce is not involved in the state board’s investigation of the 2016 allegations, but he has participated in the probe of 2018 election irregularities, Lawson said.

By February 2018, election officials were so frustrated at the lack of activity among law enforcement agencies that they called a meeting with FBI agents, local and federal prosecutors, and investigators with the State Bureau of Investigation to present evidence they had found, according to emails obtained by The Post.

In advance of the meeting, election officials distributed their lengthy investigative report “to assist federal and state prosecutors in assessing the need for additional investigation or any other action deemed appropriate,” according to a Jan. 23 cover letter sent to law enforcement officials.

An FBI agent invited to the February meeting to discuss the investigation, Julia Hanish, did not immediately respond to a request for comment.

Alice Crites and Eddy Palanzo contributed to this report.