Senate Intelligence Committee Chairman Richard Burr late Tuesday cast doubt on the veracity of a reported memo in which former FBI Director James Comey said President Trump requested he drop the FBI’s investigation into former national security adviser Mike Flynn.

“I actually believe the director might have told us that there’d been a request like that and it was never mentioned by him,” the North Carolina Republican told reporters. “So somebody’s going to have to do more than have anonymous sources on this one for me to believe that there’s something there.”