Exclusive: 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 the two probes.

While prosecutors in the Trump case aggressively focused on any first-hand interactions with the former president, including conversations about how to properly declassify documents, prosecutors in the Biden case were more concerned with the mechanics of packing and moving boxes into Biden's home in Delaware as his time as vice president came to an end.

"You wouldn't expect it to match the intensity, and it didn't," the former official said comparing the interview with Biden investigators to discussions with prosecutors in the Trump probe.

Speaking to CNN on condition of anonymity, the former official said he told federal prosecutors that Trump knew the proper process for declassifying documents and followed it correctly at times while in office.

The interview with the former official, which has not been previously reported, is the latest indication that prosecutors are seeking evidence suggesting Trump understood the process for declassifying documents. That could undercut Trump's claims that he automatically declassified everything he took with him to Mar-a-Lago.

The Justice Department recently informed Trump's legal team that he is a target in the classified documents investigation, sources familiar with the matter told CNN, a sign that prosecutors may be moving closer to indicting the former president.

The former official described working with Trump and his top advisers to properly declassify certain documents, including a 2018 congressional memo related to the Russia investigation.

The former official recalled to prosecutors how then-National Security Council lawyer John Eisenberg met with Trump in the Oval Office to discuss declassifying the memo.

When he emerged from the Oval Office, Eisenberg directed the former official to "get your declassifying tools."

The former official then huddled with White House lawyers in a nearby office redacting the memo by hand for declassification and release based on Eisenberg's guidance.

During the interview with prosecutors, the former official provided names of former Trump officials who spoke directly to the former president about the declassification process while in office. That includes Eisenberg, former White House counsel Don McGahn and former White House chief of staff John Kelly. Eisenberg, who was listed as one of a handful of custodians for Trump's presidential records at the time he left office, declined to comment when asked about his role in declassifying the 2018 memo and whether he has been contacted by the special counsel's team. McGahn did not respond to requests for comment.

CNN first reported last month that the National Archives was preparing to hand over to special counsel Jack Smith 16 additional records that show Trump and his top advisers had knowledge of the correct declassification process while he was president. Last week, CNN also was first to report that federal prosecutors have obtained an audio recording in which Trump acknowledges he held onto a classified Pentagon document about a potential attack on Iran.

It was only after obtaining the audio that prosecutors issued a subpoena for related materials. Sources previously told CNN that Trump's team returned some materials but not the document pertaining to Iran.

In the days after the FBI seized hundreds of classified and top-secret documents from Trump's Mar-a-Lago resort last August, Trump and his allies claimed the former president had a "standing order" to declassify documents he took from the Oval Office to the White House residence.

But 18 former top Trump officials told CNN they never heard any such order during their time working for Trump, including Kelly, who spent 17 months as Trump's chief of staff between 2017 and 2019.

"Nothing approaching an order that foolish was ever given," Kelly told CNN. "And I can't imagine anyone that worked at the White House after me that would have simply shrugged their shoulders and allowed that order to go forward without dying in the ditch trying to stop it."

Earlier this year, Trump's legal team told Congress that classified material was inadvertently packed up at the end of the administration. Most recently, Trump told CNN at a town hall that materials were "automatically declassified" when he took them.

However, there's no indication Trump followed the proper declassification process, and his attorneys have avoided saying so far in court whether Trump declassified records he kept.

Prosecutors have secured grand jury testimony from a number of former senior Trump officials who detailed conversations they had with the former President about the declassification process.

Mark Meadows, Trump's former chief of staff, is among those who have testified to a federal grand jury as part of special counsel Jack Smith's investigation and was asked about the former president's handling of classified documents, a source familiar with the matter told CNN on Wednesday.

Meadows was directly involved in helping Trump declassify additional documents related to the FBI's Russia investigation during his final days in office and is viewed as a critical witness in Smith's probe.

Appearing before the grand jury earlier this year, Trump's former national security adviser Robert O'Brien discussed conversations he had with the former president related to the presidential authority for declassifying documents while in office, according to a source familiar with the matter.

O'Brien testified that during those conversations with Trump, he made clear that the president has the authority to declassify but it only applies while they are in office - and even then, there is a process they have to go through, the source said.

Trump's former acting Director of National Intelligence Richard Grenell also appeared before the grand jury in April and was similarly asked about conversations he had with the former president related to the process for declassifying material, CNN reported at the time.

The Biden probe, meanwhile, remains ongoing but the special counsel overseeing that investigation, Robert Hur, does not appear to be using a grand jury at this point, sources familiar with the matter told CNN.

Hur is known to have reached out to only one witness, former Biden aide Kathy Chung. By comparison, Smith's team has interviewed dozens of witnesses in his probe of Trump and several have testified before the grand juries empaneled as part of that investigation.

The investigation into former Vice President Mike Pence's handling of classified documents was closed last Friday without a special counsel ever being appointed.

CNN's Pamela Brown and Jamie Gangel contributed to this report.