The media reported in April that Deal, a Republican, had used more than $19,000 in contributions from his state campaign account to pay legal fees related to a congressional ethics investigation.
The probe ended when Deal resigned from Congress in March to run for governor.
The ethics complaint, filed by Alpharetta resident Elizabeth Ott, said Deal violated state law by using campaign funds for his legal defense.
In her complaint, obtained by the media on Wednesday, Ott said it "would defy logic as well as the letter and intent of the statute" for a candidate's state campaign account to be tapped for an investigation related to a separate, federal office.
Deal's lawyer, Randy Evans, has maintained the payments were legal. The former congressman's campaign said they acted on the advice of Evans, a leading campaign lawyer whose clients have included Newt Gingrich.
"The commission should dismiss the case as soon as this comes before the members," Brian Robinson said Wednesday. "It's a frivolous submission."
State law stipulates that campaign funds must be used for "ordinary and necessary expenses" related to running for office. Whether a congressional ethics investigation qualifies appears to be gray area in Georgia.
Commission lawyer Tom Plank said he could find no advisory opinion or precedent addressing the use of a state fund to pay for legal fees incurred as part of a federal probe.
Congressional investigators were looking into Deal's dealings with state officials on behalf of his Gainesville auto salvage business.
In 2008 and 2009 Deal, then a member of the U.S. House, lobbied the state's revenue commissioner to preserve a lucrative no-bid contract that had funneled hundreds of thousands of dollars to his company. Those activities were first reported by The Atlanta Journal-Constitution last year.
Evans acted as Deal's lawyer in the congressional probe, accompanying Deal to 2 1/2 hour meeting in Washington with members of the Office of Congressional Ethics on Dec. 16. On Oct. 30, Evans met with investigators in Atlanta.
Deal resigned from the U.S. House on March 21 saying he wanted to focus on winning the Republican nomination for governor.
But days later the Office of Congressional Ethics released their report anyway. It said Deal's conduct may have violated House ethics rules. They recommended that the House Committee on Standards investigate. Deal resigned before the panel decided whether to take up the matter.