(CNN) Concerns over the way absentee ballots were handled in a North Carolina congressional district have led to an investigation by the state board of elections, delaying the certification of election results despite the Democrat in the race conceding.

In a surprise move Tuesday, the North Carolina State Board of Elections and Ethics Enforcement cited their own authority to initiate an investigation into the race, which Democrat Dan McCready conceded to Republican Mark Harris the day after the election. The board meets again on Friday and could reconsider its decision to not certify the results in the race.

"The state board is investigating possible irregularities with absentee ballots in the 9th Congressional District," Patrick Gannon, public information officer of the board, told CNN. The 9th district runs along the state's southern border from Charlotte to Fayetteville.

The bipartisan board voted unanimously to delay certification, allowing lawyers and investigators from the division to examine any irregularities. Investigators are currently focused on Bladen County.

The North Carolina Democratic Party submitted multiple affidavits to the board Thursday from voters whose claims say their absentee ballots were not handled properly. The letter also cites a high number of absentee requests in Bladen County as part of their claim.

At least two affidavits point to activities by Bladen County official Leslie McCrae Dowless, Jr., who has been involved with previous voter fraud accusations. Both claims say he worked for Harris. Others point to at least one unidentified woman who went door-to-door collecting and mishandling absentee ballots.

"These allegations are serious and disturbing. If true, the people's right to freely and fairly cast their votes was thoughtfully and deliberately undermined, casting a shadow over this election," North Carolina Democratic Chairman Wayne Goodwin said. "These claims must be fully investigated by state and federal authorities, and a full public hearing conducted, before certification of the 9th Congressional District election."

The board is comprised of four Democrats, four Republicans, and one unaffiliated member.

"I'm very familiar with unfortunate activities that have been happening down in my part of the state, and I am not going to turn a blind eye to what took place to the best of my understanding," said Vice Chairman Joshua Malcolm when he proposed the delay.

Both Democrats and Republicans are requesting more information from the board, which will reconvene Friday in a public and closed session. Certification of the 9th Congressional District was not on the official agenda released Thursday night, though it still could come up during the meeting.

In a statement about the decision, the board cited a state law that gives them broad authority to "take any other action necessary to assure that an election is determined without taint of fraud or corruption and without irregularities that may have changed the result of an election."

Harris's 905-vote lead amounts to a 0.4% vote margin over McCready, well below the 1% required by law had McCready wanted to petition for a recount.

"We were surprised by yesterday's developments at the State Board of Elections, but our legal team is fully engaged," Harris tweeted Wednesday. "We trust the process. This morning, we sent a letter to the SBOE asking for clarity. We continue to prepare in DC to serve the constituents of the 9th District!"

In a letter to the board, Harris's lawyer requested access, "to all information relating to the investigation as it pertains to counting or not counting votes and the number of votes involved."

The state Republican Party is publicly pushing to certify the results as quickly as possible.

"Bladen County certified the results, they certified races that were much closer and most importantly no recount was called for by the democrat opponent, NOR was any election protest filed in Bladen County, (that we are aware of The @NCSBE does not have discretion of delay certification based on facts they do NOT currently have, and may not exist[)]," North Carolina GOP Executive Director Dallas Woodhouse tweeted. "@NCSBE must certify @MarkHarrisNC9 asap or this will quickly be in court."

In a statement released Thursday night, McCready said he supports the investigation.

"(Thursday's) news reports of the serious allegations in Bladen County are troubling. We cannot allow anyone to tamper with our elections or sabotage our electoral process," he said. "I stand with voters all across the 9th District in wanting to make sure any wrongdoing is investigated and prosecuted regardless of the outcome of the election."

It's unclear how long this kind of examination of votes will take, but pressure will grow to finish the probe by January 3, when the new Congress is seated.