Republican Mark Harris speaks during a news conference Nov. 7 in Matthews, N.C. (Chuck Burton/AP)

North Carolina election officials are investigating possible irregularities with absentee ballots in the state’s 9th Congressional District, refusing to certify the race weeks after Election Day.

Unofficial results show Mark Harris, a Republican, defeating Democrat Dan McCready by 905 votes out of 282,717 cast. At a Tuesday meeting to certify statewide election results, the state Board of Elections and Ethics Enforcement declined to certify that race even as it signed off on the state’s other congressional contests.

The investigation appears to be focused on Bladen County, but an official in Robeson County said that county also has been contacted. State officials have given no other details. They cited a state law allowing them to go into closed session to ensure an election is “without taint of fraud or corruption and without irregularities that may have changed the result of an election.”

Elections officials confirmed Wednesday that an elections investigator seized completed absentee ballot request forms and absentee container envelopes Nov. 7, the day after the election.

Steve Stone, chair of the Robeson County Board of Elections, said state investigators have requested information the county board kept on an unusual number of absentee ballot requests. Stone said county elections officials began keeping logs of who dropped off large numbers of registration forms and absentee ballot requests and later reported the their concerns to the state board in August.

Stone said county residents had reported that people were going door to door, telling voters that their registrations had been dropped and they needed to re-register. They were also asked to sign an absentee ballot request form, Stone said.

“It didn’t feel right,” he said.

About 1,200 requested absentee ballots were not returned this year, Stone said, an unusually high number. Bladen County also had an unusually high number of unreturned absentee ballots.

Patrick Gannon, public information officer for the board, said the investigation is ongoing and considered a “top priority.” Investigators are working quickly to resolve the case given that a new Congress is seated in early January, he said.

The district is currently represented by Robert Pittenger, who was defeated in the Republican primary by Harris, a conservative pastor. McCready, a business executive and veteran, challenged Harris in the district, which stretches from Charlotte nearly to the state’s coastline.

Harris came out 1,557 votes ahead in Bladen County, which cast 9,398 votes in the race, according to state data. In Robeson County, McCready bested Harris by 4,728 votes of almost 31,000 cast.

Gannon said the board, which meets again Friday, won’t certify the race until the investigation is complete. Harris asked the board to expedite its review.

Under state law, the board can call for a new election if it finds that the race was tainted, a move likely to be challenged in court.

Dallas Woodhouse, executive director of the state Republican Party, threatened to take action if Harris isn’t certified quickly.

After the board’s actions Tuesday, Woodhouse launched a series of tweets aimed at the board. “.@NCSBE must certify @MarkHarrisNC9 asap or this will quickly be in court,” he said.

Harris tweeted a copy of a letter his legal team sent to the state board and said he’s preparing to serve in Congress while asking for clarity.

“We were surprised by yesterday’s developments at the State Board of Elections, but our legal team is fully engaged. We trust the process,” he said in the statement.

McCready’s campaign did not immediately respond to a request for comment.

This is not the first time absentee ballots from Bladen County have been questioned. In 2016, the state board investigated similar concerns about absentee ballots there and referred the case to the U.S. attorney for the Eastern District. The U.S. attorney’s office would not confirm whether there was an investigation.

Don Connelly, spokesman for the U.S. attorney’s office, would not confirm or deny whether there is an investigation into either the 2016 or 2018 elections.

Two other House races are uncalled by the Associated Press — the race in New York’s 27th District between Republican incumbent Chris Collins and Democrat Nate McMurray, who has conceded; and the one in California’s 21st District, where Democrat T.J. Cox this week took a lead in the county over incumbent David Valadao (R). If Cox wins and other results hold, Democrats will have gained 40 House seats in the midterm elections.