But 670 ballots were cast, according to the Georgia secretary of state's office, indicating a 243 percent turnout.

The discrepancy, included in a number of sworn statements and exhibits filed as part of a federal lawsuit against the state by election security activists, comes amid swelling public concern for the security of Georgia's voting systems. Georgia is one of four states that uses voting machines statewide that produce no paper record for voters to verify, making them difficult to audit, experts say.

And cybersecurity experts have warned that there were security flaws on the state election website leading up to the 2016 contest that permitted the download and manipulation of voter information.