"The Special Counsel's Office is part of the Department of Justice and by regulation, it was bound by that department policy," Mueller told reporters at the Justice Department.
The House Intelligence Committee chairman said there is "strong evidence" Prince lied to lawmakers about meeting with a Russian official days before Trump was sworn in.
"How many of Trump's followers or those who might otherwise be tempted to vote for him in 2020 will recoil from this moral squalor?"
"The campaign, the family, the business, the transition in the administration all approached by Russians? It was eye opening."