The FBI on Friday searched the Maryland home of John Bolton, who served as national security adviser during Donald Trump’s presidency, as part of an ongoing investigation into the handling of classified documents, according to a person familiar with the matter.

The person, who spoke on condition of anonymity, said Bolton has not been detained or charged with any crime. Messages seeking comment from Bolton’s spokesperson and the White House were not immediately returned, while a lawyer who has represented him also had no immediate response.

Bolton, a longtime Republican foreign policy official, was Trump’s third national security adviser and served for 17 months before leaving the administration amid policy clashes on Iran, Afghanistan, and North Korea. The Trump White House had previously tried to block the publication of Bolton’s memoir, alleging it contained classified material.

Earlier this year, President Trump revoked the security clearances of more than four dozen former intelligence officials, including Bolton, and canceled the security details of several former senior advisers. Bolton’s own clearance had already been revoked in January.

The search marks the latest development in the federal inquiry into the handling of classified documents, adding a new dimension to an investigation that has drawn widespread political and legal attention.