The papers were discovered at Mr Pence’s Indiana home last week, according to his attorney - marking the latest in a string of discoveries of confidential information in private residences.
The records “appear to be a small number of documents bearing classified markings that were inadvertently boxed and transported to the personal home of the former Vice President at the end of the last Administration”, Mr Pence’s lawyer, Greg Jacob, reportedly said in a letter.
He added that Mr Pence “engaged outside counsel with experience in handling classified documents”, to review records stored in his personal home after news broke that documents marked classified were found in President Joe Biden’s Wilmington residence.
Mr Pence served as Vice President from 2017 to 2021, under then-President Donald Trump.
The Justice Department is already using special counsels to investigate the presence of documents with classification markings found at the Florida estate of former president Donald Trump, and Mr Biden’s home and former Washington office.
The department says about 300 documents marked classified - including at the top-secret level - were taken from Mar-a-Lago in Florida.
Officials are trying to determine whether Mr Trump or anyone else should be charged with illegal possession of those records, or with trying to obstruct the months-long criminal investigation.
Mr Pence‘s lawyer said in his letter that the former vice president “was unaware of the existence of sensitive or classified documents at his personal residence” and “understands the high importance of protecting sensitive and classified information and stands ready and willing to co-operate fully with the National Archives and any appropriate inquiry”.
Mr Jacob said Mr Pence immediately secured the documents in a locked safe, and according to a follow-up letter from the lawyer dated January 22, FBI agents visited Mr Pence‘s residence to collect the documents.
A Justice Department spokesperson on Tuesday declined to comment on the incident, and a lawyer for Mr Pence did not immediately respond to an email seeking further elaboration.
Mr Pence told the Associated Press in August that he did not take any classified information with him when he left office.
Asked directly if he had retained any classified information upon leaving office, he said, “No, not to my knowledge.”
In a January interview with Fox Business, he described a “very formal process” used by his office to handle classified information as well as the steps taken by his lawyers to ensure none were taken with him.
“Before we left the White House, the attorneys on my staff went through all the documents at both the White House and our offices there and at the vice president’s residence to ensure that any documents that needed to be turned over to the National Archives, including classified documents, were turned over. So we went through a very careful process in that regard,” he said.