Watch: How the FBI raids on John Bolton's home and office unfolded

The FBI has been seen conducting raids at John Bolton's Maryland home and Washington DC office on Friday.

Bolton, the former national security adviser for President Donald Trump, has become one of his most vocal critics since serving in his first administration.

The search is related to an investigation over classified documents, CBS, the BBC's US news partner, reports.

Trump has said that he doesn't know what Bolton is being investigated for.