Former White House official told federal prosecutors Trump knew of proper declassification process and followed it while in office

A key former White House official was interviewed earlier this year by special counsel prosecutors investigating the handling of classified materials by both former President Donald Trump and President Joe Biden, CNN has learned.

The former career official, who was in charge of advising the Trump and Obama administrations on the declassification process, is the only known witness to be interviewed by both teams of prosecutors investigating Trump and Biden.

During those voluntary interviews, the former official told CNN there was a distinct difference in the line of questioning from prosecutors in...