The superintendents for both the House and Senate office buildings have been placed on administrative leave pending an investigation into inappropriate emails, Fox News has learned.

Multiple sources confirm to Fox that House Building Superintendent Bill Weidemeyer and Senate Building Superintendent Takis Tzamaras were placed on administrative leave pending an investigation.

At issue are inappropriate emails regarding Acting Architect of the Capitol Christine Merdon.

"The superintendents for the House Office Buildings and the Senate Office Buildings are currently on leave," a spokesperson for the Architect of the Capitol told Fox News. "It is Architect of the Capitol policy not to comment on personnel matters.”

Weidemeyer and Tzamaras both report to Merdon. Weidemeyer is in charge of the Cannon, Longworth and Rayburn House Office Buildings, and Tzamaras is in charge of the Russell, Dirksen and Hart Senate Office Buildings.

Lawmakers and congressional committees maintain their offices in those sets of buildings, located just across the street from the Capitol.

Merdon became Acting Architect of the Capitol in February after Architect of the Capitol Stephen Ayers retired last year. There have only been 11 Architects of the Capitol in U.S. history. The Architect of the Capitol is nominated by the president and confirmed by the Senate. Architects of the Capitol handle the congressional campus infrastructure, including the Capitol itself, the adjacent office buildings and the Library of Congress.

President Trump has not formally nominated anyone for the open Architect of the Capitol position.

An aide for House Speaker Nancy Pelosi, D-Calif., directed inquires about the matter to the Architect of the Capitol’s office.