"They're totally off the reservation," Weld told CNN's Alisyn Camerota Monday on "New Day," adding that the US Attorney General may need to get involved to rein in Comey.

Weld was the head of the Justice Department's criminal justice division during the final years of Ronald Reagan's tenure and said throughout the interview that his criticism of Comey's conduct was a professional critique, not political.

Pressed by Camerota on what he meant by "off the reservation," Weld said, "It means there's no way for Mrs. Clinton to know the evidentiary basis for which they made this update to their investigation, and they've said themselves they don't know. It makes it all the more unreasonable to have waded into these waters in the first place."