The former head of the IRS’ Exempt Organizations division has asked the agency to revoke the tax-exempt status of the conservative nonprofit ALEC.

Marcus Owens, a lawyer at Caplin & Drysdale, who for a decade directed the division responsible for approving organizations’ charity status, accused the American Legislative Exchange Council of illegally lobbying state lawmakers among other violations of tax law in a letter to the IRS earlier this month, Roll Call has learned.

“ALEC has deliberately and repeatedly failed to comply with some of the most fundamental federal tax requirements applicable to public charities,” he wrote. “The information in this submission also suggests, quite strongly, that the conduct of ALEC and certain of its representatives violates other civil and criminal tax laws and may violate other federal and state criminal statutes as well.”

The group, which has come under fire for its support of controversial “Stand your Ground” and voter identification laws, is organized under tax code 501(c)(3) and is barred from political activity. It can lobby, so long as attempts to influence legislation do not constitute a “substantial part” of its activities. Although its stated mission is to bring corporations and lawmakers together to craft and promote legislation, the 30-year-old group insists it does not lobby, prompting formal complaints from several government watchdog groups, including Common Cause.

But Owens’ experience with this body of tax law and reputation at the IRS combined with new evidence that ALEC may have deliberately misled the agency on its annual federal filings could deliver yet another blow to an organization already facing a public relations crisis.