Former national security adviser Mike Flynn should testify before the Senate Intelligence Committee as it investigates Russian influence on the 2016 presidential election, Vice Chairman Mark Warner said Sunday.

In separate interviews Sen. Marco Rubio, a member of the panel, said understanding what happened is essential because Russia now is attempting to influence European elections.

U.S. intelligence agencies concluded Russia hacked the email accounts of the Democratic National Committee and Clinton campaign chairman John Podesta, and also planted fake news stories on social media.

“I want to hear from General Flynn,” Warner, D-Va., told CBS’ “Face the Nation.”

Flynn was forced to resign from the Trump administration after admitting he mislead Vice President Mike Pence about contacts with Russian Ambassador Sergey Kislyak. Attorney General Jeff Sessions last week recused himself from investigation of the Russian issue after admitting he had met with Kislyak twice but neglected to mention it during his confirmation hearing.

Democrats have been pushing for a special prosecutor for the investigation, but Rubio and other Republicans say there’s no evidence that needs to happen in the absence of evidence of any illegal activity.

“I certainly don't think we're at that point at this moment. And here's why. The job of the intelligence committee is not to be a law enforcement agency. The job of the intelligence committee is to gather facts and evidence, to go through counterintelligence programs, intelligence programs, understand all the evidence and the facts that are out there about how the Russians did this, why they did this, et cetera, and put all this in a report. That is our job, to gather facts,” Rubio, R-Fla., said on NBC’s “Meet the Press.”

The issue, Rubio said, is what exactly happened, saying he had no intention of participating in a witch hunt or a coverup.

“I just returned from a trip a week ago to France and to Germany, where they have pending elections. They, too, are seeing the sort of active measures undertaken. So the purpose of the investigation is to gather facts, put them in a report to the Senate and the American people, so that we know what happened, and so that we can deal with it in the future. Because this is going to be an ongoing thing, unfortunately, not just in elections, but in our public policy debates,” Rubio said.

Rubio said if he feels the final report leaves out relevant facts, he will not sign off on it.

Senate Minority Leader Chuck Schumer, D-N.Y., said he has “some doubts” Intelligence Committee Chairman Richard Burr, R-N.C., will conduct a full investigation considering he initially expressed doubt any investigations should be conducted at all.

Schumer said Democrats on the Senate Judiciary Committee would push Rod Rosenstein, who has been nominated as deputy attorney general, so say he would be willing to appoint a special prosecutor.