THE FBI HAS searched the University of Delaware in recent weeks for classified documents as part of its investigation into the potential mishandling of sensitive government records by President Joe Biden.

The search, first reported by CNN, was confirmed to the Associated Press by a person familiar with the matter who was not authorised to discuss it publicly. They would not say whether anything was found.

A Justice Department special counsel is investigating how classified documents from Biden’s time as vice president and senator ended up in his home and former office — and whether any mishandling involved criminal intent or was unintentional.

Biden’s personal lawyers disclosed in January that a small batch of documents with classified markings had been found weeks earlier in his former Washington office and they have since allowed FBI searches of multiple properties.

In 2011, he donated his records from his 36 years serving in the US Senate to the university, which is his alma mater.

The documents arrived on 6 June 2012, according to the university, which had released photos of the numbered boxes being unloaded alongside blue and gold balloons.

Under the terms of Biden’s gift, the records are to remain sealed until two years after he retires from public life.

His Senate records would not be covered by the presidential records act, though prohibitions on mishandling classified information would still apply.

The university is the fourth known entity to be searched by the FBI after inspections of his former office at the Penn Biden Centre in Washington, where records with classified markings were initially found in a locked closet by Biden’s personal lawyers in November, and more recently of his Delaware homes in Wilmington and Rehoboth Beach.

Those searches were done voluntarily and with the consent of his legal team.

The FBI took six items that contained documents with classified markings during its January search of the Wilmington home, Biden’s personal lawyer has said.

Agents did not find classified documents at the Rehoboth Beach property but did take some handwritten notes and other materials relating to Biden’s time as vice president for review.