The House GOP has opened an investigation into Intelligence Community Inspector General (ICIG) Michael Atkinson, who Rep. Devin Nunes, R-Calif., said is either "incompetent" or "in on" the House Democrats' impeachment scheme.

"If I was the ICIG, I would provide all of the documentation," Nunes told host Laura Ingraham on Fox News' "The Ingraham Angle" on Wednesday night. "So essentially, you have to either believe he's in on it or he's incompetent."

Nunes' inquiry appears to center on the changing whistleblower forms to remove the requirement of first-hand knowledge as a condition of "urgent concern" – a point of contention lost in the hasty House impeachment inquiry proceedings, according to Nunes.

"If he's incompetent – that's what he's claiming in the letter, essentially: 'We are incompetent; we have all of these mistakes.' We need to have evidence of your incompetence. That's all we ask for in the letter. Provide us all the documentation that shows how this got changed. We are not going to take your word for it; 'oh, we made a mistake.'"

Nunes was referring to Atkinson's classified testimony before the House Intelligence Committee led by Chairman Rep. Adam Schiff, D-Calif., who has refused to make this and only this transcript public, according to Nunes.

"What he's hiding is very simple," Nunes told Ingraham. "The origins of this are shady and don't make any sense.

"So, from the time the whistleblower came forward to the IG, where the forms didn't match. It wasn't urgent, didn't have any first-hand knowledge, the form letter changed. Then, it was backdated . . . then, we had to hear from the whistleblower, and then didn't have to hear from the whistleblower.

"There are all these things," Nunes said, "the media and Democrats are hoping we had forgot about."

"I will tell you, someone is not telling the truth here, and that's why they don't want this testimony out," Nunes concluded.