Sen. Orrin Hatch declared in an exclusive Newsmax TV interview that Acting IRS Commissioner Steven Miller "basically misled me and purposefully did so" when he told legislators three times last year that tea party groups were not being targeted by the agency.
"He purposely misled me because he knew better," the Utah Republican told Newsmax on Tuesday. "That bothers me quite a bit.
"One reason they're apologizing right now is they know the investigative arm is about to take them to task -- and there are whistleblowers, too, who know that this has been wrong," Hatch said.
In an op-ed piece in USA Today on Tuesday, Miller denied the agency had singled out super PAC groups with the words "tea party" or "patriot" in their names when reviewing applications for 501(c)(4) nonprofit status.
Latest: Is Obama in Cover-Up on Benghazi? Vote Here
"The Internal Revenue Service recognizes that we should have done a better job of handling the influx of applications by advocacy groups," Miller wrote.
He said the agency had received an explosion in applications since 2010. Miller said he learned of the special treatment of such groups last May.
"Mistakes were made, but they were in no way due to any political or partisan motivation," Miller wrote. "We are -- and will continue to be -- dedicated to reviewing all applications for tax-exempt status in an impartial manner."
Hatch, the ranking GOP member on the Senate Finance Committee that oversees the IRS, told Newsmax that Miller sent legislators three letters last year, beginning in March, saying that conservative groups were not being targeted by the agency.
The senior senator has called for a congressional investigation of the matter.
"It wasn't just some lowly staffer in Cincinnati who made a mistake," Hatch told Newsmax. "Very senior management at the IRS here in Washington knew what was going on for over a year and didn't say a word.
"In fact, after the IRS leadership learned of this, they sent Congress letters saying that the targeting of conservative groups was not happening. Now this was either one of the greatest cases of incompetence that I've ever seen or it was the IRS willfully not telling Congress the truth.
"At no point in time did anyone at the IRS think it appropriate to set the record straight -- and even now I don't know that they're telling the truth," he said.
And, "it's about time" the Justice Department opened a criminal investigation into the matter, Hatch said. "This is a big scandal. The facts are not adding up here.
"This is a serious problem," he added. "The American people deserve the truth. There's no single agency in the federal government that instills more fear than the IRS."
Story continues below video.
He said Congress would be best at conducting a probe compared to an appointed special counsel or committee, and added that he was not yet prepared to pass judgment on President Barack Obama until such an inquiry was completed.
"I don't presume anything about the president or even the White House, but it's hard to believe they could get away with this without at least some of the people who are running the campaign of the president knowing about it and participating in it.
"It's a serious offense," Hatch said. "If they actually authorized this, it would be a very, very serious matter and it could involve some very serious constitutional issues."
Special: Get Dr. Brownstein Bestselling Diet Guide for Only $4.95— Save 67%. Click Here.
Another matter worthy of congressional scrutiny, Hatch said, is the disclosure Monday by The Associated Press that Justice secretly obtained two months of records of the news organization's reporters and editors.
Attorney General Eric Holder said on Tuesday that he played no direct role in the department's review of the AP records but called it part of an investigation into what he termed a grave national security leak. He launched a criminal probe into the situation.
Hatch told Newsmax that some "heads" must "roll" on this, adding, "I'm just absolutely blown away by some of the things that we've heard just this last week.
"I couldn’t believe it. It's absolutely outrageous. First, the IRS is targeting conservative organizations. Then [the Health and Human Services Department] is shaking down healthcare executives. Now, the Department of Justice is [pulling the records of reporters'] phones."
"How much more Nixonian can this administration get?" Hatch asked. "The Obama administration better answer for itself -- and quick."
© 2015 Newsmax. All rights reserved.