The Republican National Committee has filed a formal complaint against Cheryl Mills, a Clinton Foundation board member and former chief of staff to Hillary Clinton, over her involvement in the Clinton email investigation as both an immunized witness and a lawyer representing the Democratic nominee.
The RNC filed the complaint to the D.C. Court of Appeals Monday, requesting a review of the Justice Department's decision to grant Mills partial immunity during the FBI probe before she turned over her computer. Classified emails were later found on that laptop, the FBI said.
"Ms. Mills apparently used her current role as Secretary Clinton's attorney to shield herself from prosecution in the event any classified information was discovered on her laptop," wrote Raj Shah, the RNC's research director, in the letter to the Office of Disciplinary Counsel.
Shah cited D.C. "rules of professional conduct" that prohibit attorneys from working on a case in which they have "participated personally and substantially as a public officer or employee."
Mills' unusual role as both a key witness and a lawyer for the target of an FBI investigation has raised eyebrows since it was exposed publicly by the House Oversight Committee last month.
FBI Director James Comey said in a congressional hearing on Wednesday that investigators have no authority to dismiss an attorney from the legal team of a subject or target.
But his explanation did not satisfy Republicans, who were already skeptical of the FBI's decision to close the Clinton email probe in July without recommending charges for anyone involved.
Mills' attorney asked the Justice Department for immunity this year before turning over the laptop used to sort roughly 60,000 of Clinton's emails for production to the State Department.
While the former secretary of state previously claimed she turned over all of her work-related emails, the FBI found at least 2,800 previously undisclosed records that were never turned over to the government.