(CNN) -- Calling the surreptitious recording of a strategy session "Gestapo kind of scare tactics," Sen. Mitch McConnell's campaign chief said Wednesday the FBI was continuing their investigation of the audio tapes at the Senate GOP leader's campaign offices.
"The FBI is taking this very seriously," McConnell's campaign manager Jesse Benton said on Mike Huckabee's radio show. "They were at our office for about an hour today. They tell us that they're running down some leads."
Benton said the investigators were "cautious" with what they were sharing with him.
In the recordings, which appeared Tuesday on the website of the liberal magazine Mother Jones, political operatives huddling at the senator's campaign headquarters in Kentucky are heard discussing potentially attacking Ashley Judd's mental health, as well as her left-leaning politics.
Judd decided against making a bid against McConnell in March.
"This kind of stuff just has no place in a free society," Benton said. "This is Gestapo kind of scare tactics, and we're not going to stand for it. Kentuckians shouldn't stand for it, the American people, regardless of their personal political persuasion, should not stand for this."
Benton asserted later that he could "say with the utmost certainty that this did not come from anybody inside our campaign."
On Tuesday, FBI spokesman Paul Bresson confirmed the agency was "looking into the matter" of the secretly recorded tapes.