Senate Intelligence Committee Chairman Richard Burr, R-N.C., said Wednesday that the investigation into Russia's meddling in the U.S. election is one of the biggest he's seen in his years in Congress.

Burr, speaking with ranking member Mark Warner, D-Va., compared it to the Benghazi investigation.

"I'm going to tell you this one wasn't easier," he told reporters. "This was one of the biggest investigations that the hill has seen in my tenure here."

He added that staff on the committee have been given an "unprecedented amount of documents," some of which have only been seen by a few people in Congress so far. His investigation will look at Russia's efforts to influence the election, and any contacts that the Trump or Clinton campaigns might have had with Russia.

"It's safe to say that our staff currently is working through thousands of raw intelligence and analytic products," he said.

Some politicians were saying this week that the Senate committee should lead the effort, since the House Intelligence Committee is mired in a political dispute over whether Chairman Devin Nunes, R-Calif., is working too closely with President Trump. But both Burr and Warner refused to take questions about the House committee.

Other details of the Senate investigation, according to Burr: