LUMBERTON, N.C. — The congressional campaign of Mark Harris disclosed late Thursday night that it owed more than $34,000 in connection with an absentee ballot and voter turnout operation that has prompted fears of election fraud and called the North Carolina Republican’s narrow victory into question.
In a filing with the Federal Election Commission, Mr. Harris’s campaign listed an obligation of $34,310 for “reimbursement payment for Bladen absentee, early voting poll workers; reimbursement door to door.” The disclosure form said the campaign owed the money to Red Dome Group, the Charlotte-area consulting firm that Mr. Harris hired for his campaign.
Red Dome, in turn, contracted with L. McCrae Dowless Jr., a Bladen County political operative who has been accused of collecting absentee ballots from voters in a potentially illegal effort to tip the election toward the Republican nominee.
The postelection F.E.C. filing did not detail precisely how Red Dome spent the money, including how much of it was paid to Mr. Dowless or anyone he recruited for his operation, which witnesses said involved canvassers collecting absentee ballots in apparent violation of state law. But the line item was at least one indication of the Harris campaign’s aggressive political focus on Bladen County, which has a population of about 33,000 people and represents a fraction of the sprawling Ninth District.
The payment is likely to be of significant interest to state investigators, who this week served a subpoena to a lawyer for Red Dome. North Carolina officials have not made the subpoena public, but any findings could be released when the State Board of Elections and Ethics Enforcement holds an evidentiary hearing on or before Dec. 21.
Preliminary returns in the House race, which state officials have refused to certify, show Mr. Harris with a lead of 905 votes over his Democratic opponent, Dan McCready.
Red Dome has not responded to requests for comment. Mr. Harris’s campaign has denied wrongdoing, and no one is known to have been charged with a crime in connection with the efforts that Mr. Dowless oversaw this year.
The Harris campaign filed its disclosure at the end of a tumultuous day during which Mr. McCready withdrew his concession to Mr. Harris and Republican leaders began to speak publicly about the possibility of a new election, even as they expressed confidence in Mr. Harris’s integrity.
The executive director of the North Carolina Republican Party, Dallas Woodhouse, said in an interview on Thursday that if the elections board “can state there was a substantial likelihood that the race could have been altered, then we would not oppose a new election.”
North Carolina law allows the state elections board to call for a new vote if it finds that “irregularities or improprieties occurred to such an extent that they taint the results of the entire election and cast doubt on its fairness.”
Even acknowledging that a new election might be appropriate was a shift for North Carolina Republicans, who had previously demanded that the state board immediately certify Mr. Harris as the winner. But Mr. Harris and Republicans are now confronting mounting pressure over the outcome and the election’s fairness, and some Republicans said they had been concerned even about the validity of Mr. Harris’s primary victory over Representative Robert M. Pittenger.
The political perils for Mr. Harris extend beyond North Carolina. In Washington on Thursday, congressional Democrats, including Representative Nancy Pelosi, who is poised to be elected House speaker next month, issued new warnings that they might not seat Mr. Harris if the election dispute remained unsettled.
“The House still retains the right to decide who is seated,” Ms. Pelosi said in a reference to the chamber’s constitutional power to be “the judge of the elections, returns and qualifications of its own members.”
The process for a new election would depend on which government body’s decision compelled one, said Gerry Cohen, a former special counsel for the North Carolina General Assembly.
If the House refused to seat Mr. Harris and declared the Ninth District’s seat vacant, the move would trigger an entirely new election: another filing period, another primary and, eventually, another general election. But, Mr. Cohen said, a state board’s order for a new vote would lead only to a “rerun” of November’s general election. Mr. Harris would be the Republican nominee unless he died or moved out of state.
“He could move to Rock Hill, S.C.,” Mr. Cohen mused, “or to a country with no extradition treaty.”