WASHINGTON (AP) — As the National Archives became aware of classified documents in President Joe Biden’s old office in Washington, Archives officials also took custody of papers that had been shipped to a law office in Boston by the president’s personal attorney, according to emails released Friday.

No classified documents were believed to be in the Boston documents. But the emails show Archives officials were concerned enough to take them into their possession.

“Pat, we would like to pick up the boxes that are in your Boston office and move them to the JFK Library. Would it be possible to do that tomorrow?” Archives General Counsel Gary Stern wrote to Pat Moore, one of Biden’s lawyers handling the preservation of the documents, in a Nov. 8, 2022, email.

That note was among a series of emails released under a Freedom of Information request from The Associated Press and more than two dozen other entities. The notes do not go into detail on why the Archives would have sought the material that was sent to Boston. But a person familiar with the matter said Moore had been packing up papers at the Penn Biden Center, a Washington think tank where Biden had an office, that could be of use for a potential future presidential library, mostly personal details about Biden’s family.

Moore had sent the boxes to Boston, where his law offices were located, and as he continued to sort through other boxes at the Washington-based think tank he came across a classified document, said the person, who had knowledge of the investigation but was not authorized to speak publicly and spoke to the AP on condition of anonymity.

Since the November discovery, Biden’s attorneys have uncovered other documents and so has the FBI, which searched his Wilmington and Rehoboth Beach, Delaware, homes as well as the Penn Biden Center, the think tank affiliated with the University of Pennsylvania. Biden has turned over records voluntarily and agreed to the searches.

Discovery of the classified documents touched off a special counsel probe by the Justice Department.

In a Nov. 7, 2022, email, Stern advised Moore to “ensure that the boxes in your office in Boston remain secure in a locked space and are not accessed by anyone.” But no classified records appear to have been discovered in the boxes, according to the person.

The White House Counsel’s Office had no comment on the material in Boston. Biden’s personal lawyers didn’t respond to a request for comment.

The dozens of pages of emails between the National Archives and Biden’s lawyers released on Friday were mostly on arranging logistics for Archives staff to take custody of material from the Penn Biden Center.

After the news first surfaced about Biden documents, former Vice President Mike Pence said he also had found classified information at his home, and the FBI on Friday discovered an additional document with classified markings after he allowed them to search his home in Indiana. Archives officials have asked administrations going back to the Reagan presidency to comb through their records to make sure there are no more classified records or other items that should belong with the Archives.

Occasionally, former officials from various levels of government discover they are in possession of classified materials and turn them over to the authorities at least several times a year, the AP has reported. It’s been a problem off and on for decades, from presidents to Cabinet members and staff across multiple administrations stretching as far back as Jimmy Carter.

But the issue has taken on greater significance since former President Donald Trump insistently retained classified material at his Florida estate, prompting the unprecedented FBI seizure of thousands of pages of records last year.

Biden has said he was surprised by the presence of classified documents. He said the items were “to the best of my knowledge … from 1974, stray papers.”

“There may be something else. I don’t know,” Biden told PBS NewsHour’s Judy Woodruff earlier in the week.

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