Sen. Charles Grassley, chairman of the Senate Judiciary Committee, demanded the FBI release the "actual evidence" gathered in its year-long probe of Hillary Clinton's private email use after FBI Director James Comey announced Tuesday he would not recommend an indictment against the former secretary of state.

"If it wants to avoid giving the impression that the FBI was pulling punches, because many people in a similar situation would face some sort of consequence, the agency must now be more transparent than ever in releasing information gathered during its investigation," Grassley said in a statement Tuesday.

The Iowa Republican echoed concerns expressed by many Republicans that Comey had laid out what appeared to be a compelling argument that Clinton mishandled classified intelligence before announcing his decision to recommend the Justice Department decline to pursue criminal charges.

"Even Director Comey said there should be extraordinary transparency. That means more than simply giving the public a brief summary of his view of the facts," Grassley said. "It should include the actual evidence so the public can make an educated decision on its own about the judgment and decision-making of all the senior officials involved."

Comey told reporters during a press conference Tuesday morning that Clinton and her aides had been "extremely careless" in their treatment of sensitive material, including intelligence that should have been considered top secret at the time it was placed into an email on Clinton's unsecured network.

But the FBI director said he did not believe prosecutors could pursue a case given the evidence his team had uncovered.

Grassley's House counterpart, Rep. Bob Goodlatte, demanded in a letter to Comey that he explain how the FBI could withhold an indictment recommendation if it also concluded Clinton's team had repeatedly failed to handle classified information in accordance with the law.