Rep. Trey Gowdy, chairman of the House Select Committee on Benghazi, blasted Democrats on his panel Friday for obstructing the investigation into the 2012 terror attack.

"They can't think of a single witness to interview," Gowdy said of the Democrats during an interview with CNN's Wolf Blitzer. "They can't think of a single document to ask for."

Although the select committee has been conducting its probe since May 2014, it became increasingly divided as the presidential election heated up last year. The panel's discovery that Hillary Clinton used a private email address and server thrust the investigation into the spotlight in spring 2015 and made it a target for Democrats supporting Clinton.

Rep. Elijah Cummings, the committee's top Democrat, has led public criticism of the probe and has even called on Congress to dissolve the panel.

Cummings told CNN earlier that the investigation has not uncovered any new details about the 2012 attack that claimed four American lives.

"It's the same rehashing of information we already know," Cummings said. "I think Republicans are trying to draw this out into this election."

The Maryland Democrat predicted the probe would stretch into the fall.

But Gowdy dismissed suggestions that committee Republicans had invited delays in the investigation.

"He's spent more time talking to you than he has the agencies trying to get us the documents we're entitled to," Gowdy told Blitzer of his Democratic colleague.

"We gave up negotiating with Elijah and went to the White House" to secure key witness interviews, Gowdy added.

The South Carolina Republican predicted the Benghazi committee's final report would be published sometime in April. He said the release would have come sooner if federal agencies had not stonewalled the committee on documents needed for the investigation.

Gowdy noted the committee was still seeking about a dozen witness interviews, as well as two final tranches of documents.