Hicks is said to be dating the White House aide who resigned over allegations of domestic abuse from former partners.
Mueller's team is set to interview the president's former legal spokesman, who has told colleagues about a conference call with Hicks and Trump.
The panel will be meeting with Steve Bannon and FBI and Justice Department employees.
The comment reportedly sent Hicks running from the room.
“They’re going to crack Don Junior like an egg on national TV,” Bannon is quoted as saying.
Former Watergate prosecutors told Newsweek the White House communications director could find herself in legal jeopardy for fabricating statements about the Trump campaign's contacts with Russian operatives during the 2016 election.
Hicks is one of six past and current Trump administration aides whom Robert Mueller reportedly wants to question.
Hicks got her start promoting Ivanka Trump's fashion line and working for the Trump Organization.