The F.B.I. found one classified document after searching the Indiana home of former Vice President Mike Pence for five hours on Friday, an adviser to Mr. Pence said.
Mr. Pence and his aides had agreed to the search after they discovered a small number of classified documents there last month. The search, which the adviser described as “thorough and unrestricted,” also yielded six additional pages without such markings.
“The vice president has directed his legal team to continue its cooperation with appropriate authorities and to be fully transparent through the conclusion of this matter,” Mr. Pence’s adviser, Devin O’Malley, added.
The Pences were traveling when the search took place, which came a day after reports that Mr. Pence had received a subpoena from the special counsel investigating former President Donald J. Trump’s efforts to cling to power after he lost the 2020 election.
The search, while the result of an agreement with the Justice Department, has engendered suspicion and anger within the small circle of advisers close to the former vice president.
Mr. Pence’s team had been quietly negotiating the terms of a search when reports of the talks were leaked to the news media. His aides blame the Justice Department, and that experience is likely to influence future interactions related to the department’s inquiry into Mr. Trump, said a person familiar with the situation.
After President Biden disclosed that his aides had discovered classified documents from his time as vice president at his home in Wilmington, Del., and a former think tank office in Washington, Mr. Pence’s aides searched his home out of caution.
They found documents with classified markings and notified the Justice Department. The F.B.I. showed up while Mr. Pence was at the March for Life in Washington, Greg Jacob, a former adviser and Mr. Pence’s representative for dealing with records related to the presidency, wrote in a letter to the National Archives.
The disclosure renewed questions about how classified material is handled at the highest echelons of government, with both Mr. Biden and Mr. Trump the subject of special counsel investigations into the matter.
Still, Mr. Trump’s response to the discovery of sensitive government documents at Mar-a-Lago, his private club and residence in Florida, stands in stark contrast to that of Mr. Biden or Mr. Pence.
Mr. Trump for months resisted the government’s repeated attempts to retrieve the materials, including by defying a subpoena requesting their return. That prompted the F.B.I. to obtain a search warrant for Mar-a-Lago, where agents turned up more classified materials in August.
In January, Mr. Trump’s legal team provided the Justice Department with an empty folder bearing classification markings found at Mar-a-Lago, according to a person familiar with the matter.
The legal team also handed over a laptop from one of Mr. Trump’s low-level aides. The aide had uploaded thousands of pages of Mr. Trump’s daily schedule as president and in the process discovered a few pages bearing classification markings, the person said.
ABC News earlier reported the handover of the items.
Mr. Biden, by contrast, has cooperated with the Justice Department and the National Archives ever since aides found classified documents at his think tank office and his home in Wilmington, where he often spends weekends. The F.B.I. in recent weeks has searched that residence, as well as his vacation home in Rehoboth, Del.
Mr. Pence’s aides have also emphasized cooperation.
Last month, Mr. Jacob disclosed that a “small number of documents” with classified markings had been “inadvertently boxed and transported” to Mr. Pence’s home in Indiana during the waning days of the Trump administration.
“Vice President Pence immediately secured those documents in a locked safe pending further direction on proper handling from the National Archives,” Mr. Jacob wrote.
Attorney General Merrick B. Garland has declined to say whether the Justice Department’s involvement in the matter signaled an impending criminal investigation that might warrant referral to a special counsel.
Mr. Pence is weighing a bid for the White House in 2024, making him a potential rival to Mr. Trump for the Republican nomination. Mr. Biden has not yet said whether he will run for re-election, but he is widely expected to declare his candidacy for a second term.
Alan Feuer contributed reporting.