Sen. John McCain (R-Ariz.) on Sunday said Attorney General Eric Holder has “no credibility” to oversee the investigation into the recent spate of national security leaks and called for a special counsel to investigate instead.

“Mr. Holder’s credibility with Congress — there is none,” McCain said on CNN’s “State of the Union.” “We continue to have this problem with him withholding information on Fast and Furious which resulted in the killing of a Border Patrol agent in Arizona. He is close to being held in contempt. There is no credibility.”

While saying he had “great respect” for the two individuals tapped to head up the process — U.S. Attorneys Ronald Machen and Rod Rosenstein — McCain said the investigation really needs “a special counsel, someone entirely independent of the Justice Department.”

McCain has been particularly vocal about the leaks, last week accusing the “highest levels of the White House” of being responsible for them, possibly as a way to boost President Barack Obama’s image as a strong leader. On Sunday, he said he has “no idea whether the president knew or did not know” about the leaking of information.

“It’s obvious on its face that this information came from individuals who are in the administration,” McCain said. “The president may not have done it himself, but the president is certainly responsible as commander in chief.”

Watch below, via CNN: