The FBI conducted searches at two separate locations on two days on the campus of the University of Delaware in recent weeks as part of the special counsel investigation into President Joe Biden's handling of classified information, according to two sources familiar with the matter.
The searches did not uncover any materials with classified markings, although investigators did retrieve some materials that appeared to be notes for additional review, according to one of the sources.
News of the searches was first reported by CNN.
A spokesperson for the White House counsel's office declined to comment and referred questions about the matter to the Department of Justice.
A spokesperson for the University of Delaware also referred questions about the matter to the Justice Department.
The university is home to a large collection of documents, photographs, videocassettes and other files from Biden's 36 years in the Senate -- enough to fill 1,874 boxes -- according to the University of Delaware website.
A Justice Department spokesperson declined to comment.
A source familiar with the matter tells ABC News investigators are systematically going through any locations where Biden previously had office space, lived, or spent considerable time -- as well as any locations where he may have housed documents -- in order to ensure that any government materials that may be improperly stored are returned to the possession of the government and stored appropriately.