Mueller interview with Sanders may have opened up 'a new branch of the investigation': ex-federal prosecutor
White House spokesperson Sarah Sanders (Screenshot)

Appearing on MSNBC on Saturday afternoon, a former federal prosecutor said reports that White House spokesperson Sarah Huckabee Sanders sat down with investigators from special counsel Robert Mueller's office may have opened up a new line of investigation into White House lying.

Speaking with host Alex Witt, MSNBC contributor and attorney Cynthia Alksne said Sanders' answers could open up a can of worms for other White House officials who have offered up various stories on a Trump Tower meeting involving Don Trump Jr. and Russians.

"Can you ever say 'No, I don't want to talk to you?'" host Witt asked about Sanders being summoned.

"Of course you can," Alksne replied. "You can say no and wait to be subpoenaed -- absolutely you could say no."

"It's interesting, this opens up yet another branch in the investigation," the former prosecutor offered. "They're trying to find out if the president directed people to lie because what Sarah Sanders said in the press conference on August 1st in 2017 -- that the president did not dictate the statement regarding the Trump Tower meeting when, in fact, he did."

"So they want to know why did she say that?" she elaborated. "Did someone tell her to say that? Was she part of framing that? That's interesting. -- there's a bunch of other people who have the same problem."

Watch the video below via MSNBC: