John Bolton, a former adviser to US President Donald Trump who has become a persistent critic, is under federal investigation for potential unauthorised retention or removal of classified information, according to court documents connected to an FBI search of his home last month.
A search warrant application, made available on Thursday, cites possible breaches of two laws, including the Espionage Act, which makes it a crime to collect or share US national defence information without permission.
Another document catalogues the items FBI agents seized during the August 25 search of Mr Bolton's Maryland home, including two mobile phones, documents in folders labelled "Trump I-IV", and a binder labelled "statements and reflections to Allied Strikes".
The documents were unsealed by a federal judge after a group of news organisations, including Reuters, asked a court to release information relevant to the search, citing the public's interest.
"The materials taken from Amb Bolton’s home are the ordinary records of a 40-year career serving this country," his lawyer Abbe Lowell said in a statement. "Any thorough review will show nothing inappropriate was stored or kept by Amb Bolton.”
An investigation does not necessarily result in criminal charges.
Mr Trump faced charges under the Espionage Act in a now-dismissed case brought during his years out of office over alleged mishandling of classified information.
Mr Bolton was US ambassador to the UN and the White House national security adviser during Mr Trump's first term in office. Last year he called Mr Trump unfit for the presidency.
The Justice Department under Mr Trump is pursuing several critics of the administration after the President's pledges during the 2024 presidential campaign to seek retribution against his perceived adversaries.
The department agreed to release some information associated with the search, but withheld the document laying out the evidence gathered against Mr Bolton that was used to persuade a US judge to approve the action.
Prosecutors said releasing that information could compromise an continuing investigation and jeopardise US national security.

