DeKalb County's government isn't missing nearly $70 million from a sidewalk construction project, according to an internal investigation.

A memo from DeKalb Chief Operating Officer Zach Williams blames a computer error for misreporting the amount.

“There was no impropriety or overpayment,” Williams wrote in the Aug. 22 memo to county commissioners, citing a review by county police and technology officials.

Williams' memo surfaced after Viola Davis, a DeKalb resident questioning whether public money was stolen, posted it to document sharing service Scribd on Oct. 1.

The sidewalk project along South Hairston Road, completed in 2011, cost $1.39 million, according to the memo.

The discrepancy arose when the county listed the cost of the project as $72.3 million in a spreadsheet compiled in 2012.

Williams’ memo said that the county’s technology department wrote a query that showed an incorrect “approved amount” of an invoice for the sidewalk project. That erroneous amount was 100 times higher than its actual cost — $69,543,302 compared to $69,543, a difference of almost $69.5 million.

The reason why DeKalb’s computers miscalculated remains unclear, and the county has asked its software provider, Oracle, to investigate, Williams wrote. Similar inaccuracies appeared in 2.7 percent of the county’s accounts payable invoice table.

“At this time, IT does not know why the field is being updated and reported incorrectly as it is not occurring consistently,” he wrote.

Davis, a member of the Unhappy Taxpayer & Voter citizens group, said county officials need to look deeper.

“They proclaim these mistakes are due to ‘typos.’ We must demand a forensic audit,” Davis wrote on Scribd.