The Department of Justice said it will review why text messages between Peter Strzok and Lisa Page were not preserved by the FBI’s system, and if they can be retrieved.

In a letter sent to House Intelligence Committee Chairman Devin Nunes, sent Friday but released Monday, Assistant Attorney General Stephen Boyd gave notice the Justice Department was turning over texts between the two FBI agents from July 2015 to July 2017.

However, like with the letter sent by the Justice Department to the Senate Homeland Security and Governmental Affairs Committee Friday, the department told House Intel the “FBI’s system failed to retain text messages for approximately 5 months between December 14, 2016 to May 17, 2017.”

Strzok and Page were part of the FBI’s investigations into Hillary Clinton’s email server and special counsel Robert Mueller’s Russia investigator. It was previously revealed they exchanged pro-Clinton, anti-Trump messages while also maintaining an extra-marital affair.

Attorney General Jeff Sessions said Monday a review is “already underway to ascertain what occurred and to determine if these records can be recovered in any other way.”

He said “if any wrongdoing were to be found to have caused this gap, appropriate legal disciplinary action measures will be taken.”

“We will leave no stone unturned to confirm with certainty why these text messages are not now available to be produced and will use every technology available to determine whether the missing messages are recoverable from another source. If we are successful, we will update the congressional committees immediately,” Sessions said.