State elections officials in North Carolina are investigating hundreds of cases of potential voter fraud after identifying thousands of registered voters with personal information matching those of voters who voted in other states in 2012.

Elections Director Kim Strach told state lawmakers at an oversight hearing Wednesday that her staff has identified 765 registered North Carolina voters who appear to have cast ballots in two states during the 2012 presidential election.

Strach said the first names, last names, birthdates and last four digits of their Social Security numbers appear to match information for voters in another state. Each case will now be investigated to determine whether voter fraud occurred.

"Could it be voter fraud? Sure, it could be voter fraud," Strach said. "Could it be an error on the part of a precinct person choosing the wrong person's name in the first place? It could be. We're looking at each of these individual cases."

WRAL.com reported that 81 residents who died before election day were recorded as casting a ballot. While about 30 of those voters appear to have legally cast ballots before election day, Strach said "there are between 40 and 50 [voters] who had died at a time that that's not possible."

"We have the 'Walking Dead,' and now we've got the 'Voting Dead,'" said state Sen. Bob Rucho, R-Mecklenburg. "I guess the reason there's no proof of voter fraud is because we weren't looking for it."

Strach cautioned, however, that in several past cases, instances of so-called zombie voters turned out to be the result of clerical errors.

"We're in the process of looking at each of these to see," Strach said. "That means either a poll or precinct worker made a mistake and marked the wrong person, or someone voted for them. That's something we can't determine until we look into each case."

A law passed last year by the Republican-dominated state legislature required elections staff to check information for North Carolina's more than 6.5 million voters against a database containing information for 101 million voters in 28 states.

The cross-check found listings for 35,570 North Carolina voters whose first names, last names and dates of birth match those of voters who voted in other states. However, in those cases middle names and Social Security numbers were not matched.

The analysis also found 155,692 registered North Carolina voters whose information matched voters registered in other states but who most recently registered or voted elsewhere. Strach said those were most likely voters who moved out of state without notifying their local boards of elections.

Republicans leaders immediately touted the preliminary report as evidence they were justified in approving sweeping elections changes last year that include requiring voters to present photo ID at the polls, cutting days from the period for early voting and ending a popular civics program that encouraged high school students to pre-register to vote in advance of their 18th birthdays.

“That is outrageous. That is criminal. That is wrong, and it shouldn’t be allowed to go any further without substantial investigations from our local district attorneys who are the ones charged with enforcing these laws,” state Sen. Thom Goolsby, R-Wilmington, told the Charlotte Observer.

State House Speaker Thom Tillis, R-Mecklenburg, and Senate Leader Phil Berger, R-Rockingham, issued a joint statement Wednesday on what they termed as the "alarming evidence."

"While we are alarmed to hear evidence of widespread voter error and fraud, we are encouraged to see the common-sense law passed to ensure voters are who they say they are is working," said the statement. "These findings should put to rest ill-informed claims that problems don't exist and help restore the integrity of our elections process."

However, other states using the cross-check system have yielded relatively few criminal prosecutions for voter fraud once the cases were thoroughly investigated.

Only 11 people were prosecuted on allegations of double-voting as a result of the 15 states that performed similar database checks following the 2010 elections, according to data compiled by elections officials in Kansas, where the cross-check program originated.

Bob Hall, director of the non-profit group Democracy North Carolina, cautioned officials not to jump to conclusions based on the preliminary database check.

"I know there is more than one Bob Hall with my birth date who lives among the 28 states researched," Hall said. "There may be cases of fraud, but the true scale and conspiracy involved need to be examined more closely before those with political agendas claim they've proven guilt beyond a reasonable doubt."

Voting rights advocate Bob Phillips of Common Cause NC told WRAL.com that while he is concerned about the report, it still doesn't justify requiring voters to present photo ID at the polls.

"I think a lot of [lawmakers] are saying, 'Aha, this proves what we did,'" Phillips said. "But if I have an ID, how is that going to stop me from voting in North Carolina if I've already voted in Florida?"

The Associated Press contributed to this report.