WASHINGTON — While special counsel Robert Mueller’s probe into possible Trump campaign connections to Russian interference in the 2016 election grabs headlines, the bipartisan investigation by the Senate Intelligence Committee continues to move forward, sometimes under the national radar, the committee's vice chair said Sunday.

“We actually interviewed literally a couple hundred individuals, many times without actually even the knowledge of the press,” the Senate Intelligence Committe Vice Chair Sen. Mark Warner, D-Va., said in an interview on “Meet The Press."

“We’ve worked with a lot of these individuals cooperatively. We’ve got more to do. Obviously Mueller’s got a different lane and his people fall into the realm of legal jeopardy. They may be less willing to talk to us. But I’ve been very pleased so far in terms of the level of cooperation we’ve had from virtually everyone.”

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Last Monday, former Trump campaign chairman Paul Manafort and his associate Rick Gates were indicted by a federal grand jury on 12 charges, including conspiracy against the United States, money laundering, and being an unregistered foreign agent.

Hours later, Mueller’s office announced that George Papadopoulos, a foreign policy adviser on the campaign, pled guilty to making false statements to the FBI related to the investigation. During the campaign, Papadopoulos offered to use his “Russian contacts” to set up a meeting between Donald Trump and Russian Vladimir Putin, NBC News has reported. That meeting never happened during the campaign.

Warner on Sunday wouldn’t specifically confirm or deny whether his committee had already spoken with Papadopoulos.

“I’m not going to talk about which witnesses that we’ve seen or not seen,” he said. “But the chairman and I did indicate that Mr. Papadopoulos had been on our screen for a long time.”

Sen. James Lankford, R-Okla., also a member of the Senate’s Intelligence Committee, added in a separate "Meet the Press" interview that the committee is interested in finding out about anyone else within the Trump campaign who reacted to overtures by Russians.

“The Russians reached out to him, he seemed to reach back out to them and say, ‘sure, I’d be very interested in that,'” Lankford said of Papadopoulos. “Now the next challenge is, did anyone else from the campaign do that? He was a volunteer, he was someone that seemed to advertise himself around the world as being more influential in the campaign than he actually was, and it looks like the Russians took the bait on that.”

NBC News reported Sunday morning that Mueller has enough evidence to bring charges in their investigation into former White House National Security Adviser Michael Flynn and Flynn's son. Earlier in the morning, Lankford said that the committee was interested in hearing from both of them and learning more about what roles they may have played.

“That’s actually what we’re going to try to ask and find out,” the senator said on “Meet The Press.” “We want to be engaged in all areas in that and ask them both of them every question we can possibly get out. At the end of this, as you and I have talked about before, a lot of Americans are going to say, ‘did you ask this person this question?’ We’re going to make sure all of that gets out.”

Warner wouldn't say whether or not Flynn and his son have been cooperative with their investigation.

"The way we get the kind of cooperation with the witnesses is, frankly, to not share the kind of weekly box score of who we’ve seen and who we’ve not seen," he said. "We’ve got a lot of folks that we have seen. More folks than we need to. And end of the day, what we owe the American people is the truth and most importantly, how we make sure that we don’t have a foreign power and a foreign power like Russia intervene again in our elections."