Georgia Secretary of State Brian Kemp, the Republican candidate for governor, said Sunday that he was investigating the state Democratic Party for an attempted hack of the voter registration system — a claim met with a swift response from Democrats charging him with a shameless "political stunt" two days before Election Day.

Kemp, who is in a neck-and-neck race with Stacey Abrams, alleged that the state Democratic Party made a "failed attempt to hack the state's voter registration system" and announced that his office was opening an investigation into the party. Kemp said his office alerted the Department of Homeland Security and the FBI, but he offered no evidence to back up his allegation.

"While we cannot comment on the specifics of an ongoing investigation, I can confirm that the Democratic Party of Georgia is under investigation for possible cyber crimes," Candice Broce, press secretary for the secretary of state, said in a statement. "We can also confirm that no personal data was breached and our system remains secure."

Broce told NBC News that the office will release additional information "as soon as we can."

On Sunday afternoon, Kemp's office released a new statement saying the secretary of state opened the investigation "after receiving information from our legal team about failed efforts to breach the online voter registration system and My Voter Page."

"We are working with our private sector vendors and investigators to review data logs," Kemp's office said. "We have contacted our federal partners and formally requested the Federal Bureau of Investigation to investigate these possible cyber crimes."

Democrats blasted the announcement, which comes amid the backdrop of one of the nation's most fiercely contested races ahead of Election Day on Tuesday.

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Rebecca DeHart, executive director of the state's Democratic Party, said in a statement that the investigation was "yet another example of abuse of power by an unethical Secretary of State."

"To be very clear, Brian Kemp's scurrilous claims are 100 percent false, and this so-called investigation was unknown to the Democratic Party of Georgia until a campaign operative in Kemp's official office released a statement this morning," DeHart said. "This political stunt from Kemp just days before the election is yet another example of why he cannot be trusted and should not be overseeing an election in which he is also a candidate for governor."

DeHart later added that Georgians "of all political stripes are very concerned about election security and the security of Georgians' personal information."

"The Democratic Party of Georgia shares that concern," she said, "but we did not create, discover, or attempt to take advantage of the deeply vulnerable system used by the Secretary of State's office."

During an interview Sunday on CNN's "State of the Union," Abrams called Kemp's announcement "a desperate attempt on the part of my opponent to distract people" from judicial rulings that had gone against decisions he made as secretary of state, the office that oversees voting in the state.

In one such battle, a federal judge ruled against Kemp on Friday and decided that the state must make it easier for some people flagged under Georgia's "exact match" law to vote.

"He is desperate to turn the conversation away from his failures, from his refusal to honor his commitments and from the fact that he's part of a nationwide system of voter suppression that will not work in this election because we're going to outwork him, we're going to out vote him ... and we're going to win," Abrams said.

The race's most prominent back-and-forth involves Kemp's role as the state's top election official. The controversy centers on Kemp's having purged tens of thousands of voters, most of whom are black, from voter rolls. Kemp has denied that he is trying to suppress the black vote, saying he is simply following the law.

Abrams has accused Kemp of undermining confidence in democracy and creating "an atmosphere of fear" for voters through his actions as secretary of state — allegations that Kemp has called "a farce."

Former President Jimmy Carter, a Georgian, recently called for Kemp to resign.

Also Sunday, Kemp tweeted a photo of five people he said were dressed as members of the New Black Panther Party and were holding signs in support of Abrams. That group is described by the nonprofit Southern Poverty Law Center as "a virulently racist and anti-Semitic organization whose leaders have encouraged violence against whites, Jews and law enforcement officers."

How radical is my opponent? Look at who is backing her. The New Black Panther Party is "a racist...antisemitic organization whose leaders have encouraged violence against whites, Jews, & law enforcement" RT if you agree that Abrams & the Black Panthers are TOO EXTREME for GA! pic.twitter.com/oJXdTHgcym — Brian Kemp (@BrianKempGA) November 4, 2018

Last month, Kemp came under fire after he posed for a photo with an anti-Muslim extremist.

Abigail Collazo, a spokeswoman for the Abrams campaign, said in a statement that Kemp "is the only candidate in this race who has posed for pictures with supporters wearing racist, hate-filled T-shirts and refused to denounce them, while Abrams continues to condemn any racist, anti-Semitic, or otherwise discriminatory words and actions."

Polling has shown the race to be tight. An October NBC News/Marist poll found that the race was essentially tied, with likely voters favoring Kemp by 49 percent to 47 percent, a spread within the poll's margin of error. Among registered voters, the two candidates are tied at 47 percent.

If she wins, Abrams would become the nation's first black female governor.