Former deputy national security adviser Matthew Pottinger is likely to testify on Thursday before the House committee probing the 6 January attack on the US Capitol.
He is slated to appear alongside former deputy press secretary Sarah Matthews, CNN reported. The committee is, however, yet to publicly confirm the report.
Mr Pottinger was the highest-ranking White House official to have stepped down immediately after the riot.
According to a video testimony played by the committee during a hearing early in June, he said he decided to resign after former president Donald Trump tweeted saying that the then vice president Mike Pence should have shown more courage.
“I read that tweet. And made a decision at that moment to resign,” Mr Pottinger had said. “That’s where I knew that I was leaving that day, once I had read that tweet.”
Ms Matthews is also expected to testify about the events unfolding in the West Wing during the insurrection.
The committee is expected to use the hearing to lay out the “dereliction of duty” by Mr Trump on that day.
Earlier hearings have detailed chaos in the White House while aides and outsiders were begging the president to tell rioters to leave.
There still remain unanswered questions about what Mr Trump was doing as the violence unfolded.
“This is going to open people’s eyes in a big way,” said representative Adam Kinzinger, a member of the House committee investigating the riot who will help lead Thursday’s session. ”The president didn’t do anything.”
Democratic Rep Elaine Luria, who would be leading the hearing along with Mr Kinzinger, told CNN that they would be going through “pretty much minute by minute” actions of Mr Trump.
“He was doing nothing to actually stop the riot,” she told the outlet.
The upcoming hearing will be the first in the prime-time slot since the 9 June debut, which was viewed by about 20 million people.
