The FBI is searching the Maryland home and Washington office of John Bolton – who served in US President Donald Trump’s first administration as national security adviser but later became critical of the president – as part of an investigation into the handling of classified information, a person familiar with the matter said.

Bolton was not detained and has not been charged with any crimes, said the person, who was not authorised to discuss the investigation by name and spoke to The Associated Press on the condition of anonymity.

After the search at Bolton’s home started, he was spotted on Friday morning standing in the lobby of the Washington building where he keeps an office and talking to two people with “FBI” visible on their vests. He left a few minutes later and appeared to have gone upstairs in the building. Agents were seen taking bags into the office building through a back entrance.

The searches appear to be the most significant public step the Justice Department has taken against a perceived enemy of the president, and they’re likely to elicit fresh criticism that the Trump administration is using its law enforcement powers to go after the Republican’s foes. The searches of Bolton’s home and office come as the Trump administration has taken steps to examine the activities of other critics, including by authorising a grand jury investigation into the origins of the Trump-Russia probe.

Messages left with a spokesperson for Bolton were not immediately returned, and a lawyer who has represented Bolton had no immediate comment.

The White House did not comment and referred questions about the probe to the FBI. The Justice Department also had no comment, but leaders appeared to cryptically refer to the search of Bolton’s home in a series of social media posts on Friday morning.

FBI Director Kash Patel, who in a 2023 book he wrote included Bolton in a list of “members of the Executive Branch Deep State,” posted on X: “NO ONE is above the law… @FBI agents on mission.” Attorney General Pam Bondi shared his post, adding: “America’s safety isn’t negotiable. Justice will be pursued. Always.”

The Justice Department is also conducting mortgage fraud investigations into Democratic Senator Adam Schiff of California and New York Attorney General Letitia James, who brought a civil fraud lawsuit against Trump and his company, and ex-Trump prosecutor Jack Smith faces an investigation from an independent watchdog office. Schiff and James have vigorously denied any wrongdoing through their lawyers.

In an ABC interview earlier this month, Bolton was asked about whether he was worried about the Trump administration taking action against him. Bolton said Trump had “already come after” him by taking away his security detail, and he added: “I think it is a retribution presidency.”

Bolton served as Trump’s third national security adviser for 17 months and clashed with him over Iran, Afghanistan and North Korea. He faced scrutiny during the first Trump administration over a book he wrote about his time in government that officials argued disclosed classified information, but the Justice Department in 2021 abandoned its lawsuit and dropped a separate grand jury investigation.

Bolton’s lawyers have said he moved forward with the book after a White House National Security Council official, with whom Bolton had worked for months, said the manuscript no longer contained classified information.

On his first day back in office this year, Trump revoked the security clearances of more than four dozen former intelligence officials, including Bolton. Bolton was also among a group of former Trump officials whose security details were canceled by Trump earlier this year.

Bolton’s scathing book, The Room Where It Happened, portrayed Trump as grossly ill-informed about foreign policy and said he “saw conspiracies behind rocks, and remained stunningly uninformed on how to run the White House, let alone the huge federal government.”

Trump responded by slamming Bolton as a “crazy” war-monger who would have led the country into “World War Six”.

Bolton served as US ambassador to the United Nations under President George W Bush and also held positions in President Ronald Reagan’s administration. He had considered running for president in 2012 and 2016.

In 2022, an Iranian operative was charged in a plot to kill Bolton in presumed retaliation for a January 2020 US airstrike that killed the country’s most powerful general. Bolton had by then left the Trump administration but tweeted, “Hope this is the first step to regime change in Tehran.”