Graham said he has "reason to believe" the communications exist and said he would like to see them turned over to the Senate Judiciary Committee, of which he is a member.
"If there was a communication to the Department of Justice about an ongoing investigation from people who are the subject of the investigation, I want to know that," he said.
His claim comes as President Trump has been accused of obstructing the Michael Flynn investigation, according to a report on a memo of former FBI Director
Graham weighed in on the appointment of former FBI Director Robert Mueller as special counsel to investigate any ties between Russia and the Trump campaign. Graham said he hasn't seen any evidence of criminal activity by President Trump so far.
He said the appointment of a special counsel "knocks Congress out of the game for all practical purposes."
"Now I think the public will be one of the biggest losers of this decision," said Graham, explaining that public hearings with Comey or other figures are now unlikely.
Comment: The Justice Dept wanted to stop the FBI from alerting Congress to Killary's emails