New court filings provide more detail about the basis for an FBI investigation into President Trump’s former national security adviser John Bolton.

The affidavit, initially filed with the courts on Aug. 21, shows federal agents thought Bolton might have violated the Espionage Act by mishandling national defense information, The affidavit appears to confirm the Trump administration suspected Bolton may have wrongly revealed classified information in drafting his memoir, “The Room Where It Happened,”according to The Hill newspaper.

In addition, the federal probe appears to be focusing on emails Bolton sent while still working at the White House that were gathered by a foreign intelligence service, The New York Times reported last month.