The probe — which is said to involve classified documents — was first launched years ago, but the Biden administration shut it down “for political reasons,” according to a senior US official.

The FBI searched the home of former Trump official John Bolton as part of an investigation into the handling of classified information, according to officials.

The searches of Bolton’s home and office come as the Trump administration has taken steps to examine the activities of other Trump critics, including by authorizing a grand jury investigation into th...