The FBI has launched an investigation into apparent leaks of classified information involving a cyberwarfare program against Iran, a US official said Wednesday.
FBI spokesman Paul Bresson had no comment on the reported investigation.
Sen. Saxby Chambliss, ranking Republican on the Senate Intelligence Committee, said he was informed that an FBI inquiry was under way.
The senator from Georgia and other leaders of the House and Senate Intelligence Committees issued a joint statement Tuesday deploring the apparent leaks.
The White House pushed back against suggestions it could be leaking classified information for political purposes.
"This administration takes all appropriate and necessary steps to prevent leaks of classified information or sensitive information that could risk ongoing counterterrorism or intelligence operations," spokesman Jay Carney said Wednesday aboard Air Force One as the president traveled to campaign events on the West Coast.
"Any suggestion that this administration has authorized intentional leaks of classified information for political gain is grossly irresponsible."
Asked about the White House's response, Sen. John McCain told CNN International's "Amanpour," "I would expect nothing else from the White House. But the fact is that the portrayal of the president in these stories is nothing short of heroic."
The ranking member of the Senate Armed Services Committee added, "Clearly, administration officials were involved."
McCain, R-Arizona, said he has "great faith" in the FBI but that a matter as weighty as national security "probably deserves a special counsel."
Feinstein told CNN's "The Situation Room with Wolf Blitzer" that she didn't believe any of the information came from the top ranks of the White House.
McCain and Chambliss cited other recent leaks as well, including information on the administration's efforts to expand its drone program and the president's involvement in "kill lists" against militants in Yemen and Pakistan.
Also, the public airing of details surrounding a recently disrupted bomb plot in Yemen by al Qaeda in the Arabian Peninsula angered intelligence and national security officials.