According to CNN, the National Archives is considering sending letters to all living former presidents and vice presidents asking them to comb through their files to guarantee there are no confidential documents.
Following revelations that former Vice President Mike Pence had sensitive materials in his Indiana home, representatives for four past presidents have all notified CNN that they do not have any classified information in their possession.
The discovery of sensitive materials in Pence's house in Carmel, Indiana, was the third in recent months. Former President Donald Trump and President Joe Biden have both been scrutinized after classified material was discovered in their houses.
All classified data had been given to the National Archives after the previous presidents Bill Clinton, George W. Bush, Barack Obama, and the late George H.W. Bush left office, according to statements made by their respective representatives to CNN.
None of the former presidents' representatives mentioned conducting additional searches of residences or workplaces that may contain records.
Instead, they reaffirmed the procedures those officials had followed when they left the White House in 1993, 2001, 2009, and 2017.
Representatives for Bush and Obama used the same procedure when turning over both classified and unclassified information to the National Archives, the report said.
"All of President Clinton's classified materials were properly turned over to NARA in accordance with the Presidential Records Act," Clinton's office said.
According to Obama's office, the Archives has always had physical and legal control of those records.
When George H.W. Bush left office, he immediately turned over all of his files, including his personal papers. Then, as the Archives combed through everything, his personal documents were returned to him, according to sources acquainted with his presidential papers.
According to a source familiar with the Archives, former President Jimmy Carter did not uncover any errant classified materials.
A spokesperson for former Vice President Al Gore said, "When leaving the White House in January 2001, Vice President Gore and his staff turned over materials to NARA in accordance with the Presidential Records Act. No classified materials have been discovered in the 22 years since VP Gore left public office."
Sources familiar with the records of former Vice President Dick Cheney said he also turned everything over when he left the White House and is in compliance, and former Vice President Dan Quayle confirmed to CNN that everything was turned over and he never had any problems with finding classified papers after leaving office.