House Republicans are demanding to know why Justice Department officials entered into a pair of "side agreement" with Cheryl Mills and Heather Samuelson — two of Hillary Clinton's top former aides who went on to become her personal attorneys during the FBI's email investigation — that allowed law enforcement agents to destroy their laptops after searching their hard drives for evidence.

In a letter from House Judiciary Committee Chairman Bob Goodlatte to Attorney General Loretta Lynch on Monday, Goodlatte questioned why the destruction of the laptops used to sort Clinton's emails was included in immunity deals that already protected Mills and Samuelson from prosecution based on the records recovered from their computers.

"Like many things about this case, these new materials raise more questions than answers," Goodlatte wrote of the "side agreements," which lawmakers were allowed to read even though they have not yet been released in full to members of Congress.

The House Oversight Committee exposed publicly the immunity agreements provided to Mills and Samuelson last month. Critics quickly questioned why the two Clinton aides were permitted to accompany Clinton to her early July interview with the FBI if they had already become immunized witnesses in the case. The FBI said that because it was a voluntary interview, investigators had no control over who Clinton brought with her.

In his letter, Goodlatte noted that the immunity agreements revealed the FBI agents limited their search to documents authored before Jan. 2015. The Republican chairman argued such parameters prevented investigators from examining potential proof of the destruction of evidence that may have occurred after that date, and that the deals offered to Mills and Samuelson already protected the aides from prosecution related to their alleged roles in the deletion of federal records.

An attorney representing both Mills and Samuelson negotiated immunity deals for the Clinton aides before agreeing to hand over their laptops.