State Department officials “failed to disclose” a special employment status granted to Cheryl Mills who was former Secretary of State Hillary Clinton’s chief of staff, according to Sen. Charles Grassley.

Mills was designated a “Special Government Employee,” and may have “abused her access” for the benefit of former President Clinton and the Clinton family’s foundation, Grassley, the Iowa Republican, charged Tuesday in a letter to Secretary of State John Kerry.

Grassley is chairman of the Senate Judiciary Committee.

Special government employee status allowed Mills to be paid simultaneously for several months in 2009 as Clinton’s chief of staff at the State Department and as a board member for the Clinton Foundation.

The SGE designation also exempted Mills from certain criminal and civil conflict-of-interest and other ethics laws that usually cover federal employees, as well as from other regulations governing outside income and affiliations while on the government payroll.

As chief of staff, Mills was one of a small circle of State Department officials who reviewed the former chief executive’s proposed speeches and business arrangements to prevent conflicts of interest with Mrs. Clinton’s duties as secretary of state.

Clinton was paid millions of dollars for the speeches by foreign governments, individuals, foundations and corporations.

The Grassley charges widens the group of State Department employees who received the special designation during Clinton’s tenure as the country’s chief diplomat.

Huma Abedin, Clinton’s deputy chief of staff, also worked in the State Department as an SGE while service at a consulting firm owned by a close former aid to the former president and at the Clinton Foundation.

Abedin is now vice chairwoman of Hillary Clinton’s 2016 Presidential campaign.

Former Maryland Lt. Governor Kathleen Kennedy Townsend was also an SGE at the State Department under Secretary Clinton. Townsend is now chairman of “Correct the Record,” a pro-Hillary Super-PAC.

Clinton also conferred the SGE status on John Podesta, who is now chairman of her presidential campaign.

Other prominent Democrats who got the SGE designation during Clinton’s tenure at the department included former Ambassador Stuart Eizenstadt, former Sen. Chuck Robb of Virginia, former Clinton White House trade advisor Thomas McLarty and Democratic donor Elizabeth Bagley Frawley.

Grassley charged that the State Department had “failed to disclose Ms. Mills’ 2009 SGE status” when it released an official list of SGE employees in February 2014, thereby camouflaging her dual role serving Secretary Clinton and the Clinton Foundation.

Grassley said “her simultaneous relationship with the State Department, the Clinton Foundation, and her actions on behalf of  President Clinton’s paid speaking engagements raise important questions.”

Grassley noted as well that “it is unclear if the State Department took any action to make certain that Ms. Mills did not abuse her access to the agency for the benefit of the Clinton Foundation.”

Mills’ relationship with the Clinton’s predated her work at the State Department. She served in the transition team for the Clinton-Gore transition team in 1992 and was a top legal adviser to President Clinton. She was also a member of his defense team during his impeachment proceedings before Congress.