"You are right that you cannot have somebody, a friend of mine -- Jeff Sessions -- who was on the campaign and who was an appointee," California Rep. Darrell Issa said Friday on HBO's "Real Time with Bill Maher." "You're going to need to use the special prosecutor's statute and office ... not just to recuse. You can't just give it to your deputy. That's a political appointee."
Issa said an investigation might not reveal any fault on the part of Trump's associates, but a special prosecutor is needed given the growing awareness of the dangers posed by Russian President Vladimir Putin.
"We're going to have to do it," he told Maher. "There may or may not be fault, but the American people ... are beginning to understand that Putin murders his enemies."
"We're going to ask the Intelligence Committees of the House and Senate to investigate within the special areas that they oversee," added Issa, who sits on the House Oversight and Foreign Affairs committees.
Former national security adviser Michael Flynn resigned earlier this month after acknowledging he did not provide Vice President Mike Pence with a full account of his communications with Russian Ambassador Sergey Kislyak -- conversations that reportedly involved US sanctions.
The concerns Issa expressed about Sessions' close relationship with Trump and how that could affect the investigation are shared by other lawmakers.
While many Democrats have spoken out about the need for an investigation into the Trump campaign's reported communications with Russians known to US intelligence, responses from Republicans have been mixed. Some GOP lawmakers have said the investigations should focus on the leaks from the intelligence community rather than the reported campaign contact with Russian individuals.
Earlier this week, multiple U.S. officials briefed on the matter told CNN
that the FBI rejected a recent White House request to publicly knock down media reports about communications between Trump's associates and Russians known to US intelligence during the presidential campaign.
But a White House official said late Thursday that the request was made only after the FBI indicated to the White House that it did not believe the reporting to be accurate.
White House officials sought the help of the intelligence community investigating the issue to say reports were incorrect and that there had been no contacts, the officials said. Reports of contacts between the camps were first published by CNN on February 14.
After the FBI rebuffed the administration's request, the Trump administration also reached out to members of Congress to counter the stories, The Washington Post first reported.
House Intelligence Committee Chairman Devin Nunes was one of the lawmakers involved in those conversations. The California lawmaker had already been disputing the reports with journalists when he spoke to the White House, and at its request, he reached out to an additional reporter to discuss the reporting, a Nunes spokesman told The Washington Post.
"Chairman Nunes did nothing inappropriate," Jack Langer, communications director for the intelligence panel, told CNN Saturday in response to questions about the Washington Post's report. "He made inquiries into the allegations published by The New York Times and couldn't find evidence to support them," Langer said, referring to that newspaper's earlier report that the Trump campaign was in contact with Russian officials.
"So he told that to multiple reporters, and then a White House aide asked if he would speak to one more, Langer added. "So he spoke to that reporter as well, telling that person the same thing he told the other reporters."
Senate Intelligence Committee Chairman Richard Burr told The Washington Post he "had conversations about" Russia-related news reports with White House officials and communicated with news organizations to dispute reports.
"I've had those conversations," the North Carolina Republican said. "I felt I had something to share that didn't breach my responsibilities to the committee in an ongoing investigation."
Senate Intelligence Committee Vice Chairman Mark Warner said he contacted CIA Director Mike Pompeo and Burr to express his "grave concerns" about the communications.
"I have called Director Pompeo and Chairman Burr to express my grave concerns about what this means for the independence of this investigation and a bipartisan commitment to follow the facts, and to reinforce that I will not accept any process that is undermined by political interference," the Virginia Democrat told CNN in a statement.
"I am consulting with members of the Intelligence Committee to determine an appropriate course of action so we can ensure that the American people get the thorough, impartial investigation that they deserve, free from White House interference," he said.
Warner challenged Republicans to take the investigation seriously.
"It will be up to Republican leadership to demonstrate in the days ahead that they are capable of pursuing this investigation 'wherever it leads,'" he added. "I have said from the very beginning of this matter that if SSCI [Senate Select Committee on Intelligence] cannot properly conduct an independent investigation, I will support empowering whoever can do it right."