The evidence was uncovered by Kevin Shwedo, the director of the Department of Motor Vehicles, during an extensive review of data related to the state's new voter ID law, officials said.

"Director Shwedo's research has revealed evidence that over 900 deceased people appear to have 'voted' in recent elections in South Carolina," Attorney General Alan Wilson said. "This is an alarming number, and clearly necessitates an investigation into potential criminal activity. I have asked SLED Chief Keel to review Director Shwedo's research."

Letter from AG to SLED Chief

In a letter to Chief Keel, Wilson wrote, "No right is more precious than the right to vote and no process is more important in terms of integrity than the election process. Voter fraud cannot be tolerated. Therefore, I respectfully request that SLED conduct a preliminary inquiry into these voting irregularities."

The state's voter ID law was passed in 2011, and requires voters to show photo identification. It has been challenged by the U.S. Department of Justice.