The FBI found an additional classified document at the property of former vice president Mike Pence on Friday, two weeks after the Republican acknowledged having a "small number" of government files at his home.

Pence's spokesman Devin O'Malley said in a statement to US media that agents had turned up the material in a "thorough and unrestricted" five-hour search of the Carmel, Indiana house, conducted with Pence's consent.

They removed "one document with classified markings and six additional without such markings that were not discovered in the initial review by the vice president's counsel," he added.

The search came after Pence, who is weighing a run for the presidency in 2024, reported last month that an aide had uncovered classified papers, likely taken with other material when he left the White House in January 2021.

That followed searches of the homes of President Joe Biden and former president Donald Trump that also turned up classified documents.

Former top US officials are obliged to hand over all official papers from their time in the White House to the National Archives.

A scandal ignited when FBI agents raided Trump's Mar-a-Lago home in Florida last August and found significant amounts of classified documents, after Trump maintained there weren't any.

That followed months of requests from the National Archives for all the materials Trump took with him.

The former president is being probed by an independent Justice Department prosecutor for illegally taking and retaining the classified papers, as well as obstruction for hindering the investigation.

After Trump's case erupted, classified papers were then discovered in a Washington office that Biden used before he became president.

That led to FBI searches permitted by Biden in his Wilmington, Delaware home, where more documents were found, and his vacation home in Rehoboth Beach, Delaware, where none were found.

"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," added O'Malley in the statement quoted by multiple US media outlets.

O'Malley didn't respond to AFP's request for comment.

The latest find capped two days of unwelcome headlines for Pence, who was reportedly subpoenaed Thursday in a separate federal probe into Trump's effort to overturn the 2020 election and his role in the 2021 assault on the US Capitol.