(Carolyn Kaster/AP)

The independence and speed of two veteran prosecutors named by the Justice Department to investigate leaks of national security information could determine whether the controversy settles quickly or blossoms into an election-year problem for President Obama.

The heads of the congressional intelligence committees said on a Sunday talk show that it was a “good start” for Attorney General Eric H. Holder Jr. to name U.S. attorneys from the District and Maryland to investigate a series of national security leaks that have drawn bipartisan criticism.

But Sen. Dianne Feinstein (D-Calif.), chairman of the Senate Select Committee on Intelligence, appearing along with her House counterpart, Rep. Mike Rogers (R-Mich.), on CBS’s “Face the Nation,” said that an investigation headed by U.S. Attorneys Ronald C. Machen Jr. of the District and Rod J. Rosenstein of Maryland must be “nonpartisan, it has to be vigorous and it’s got to move ahead rapidly.”

The situation presents combustible election-year elements: the delicacy of the administration investigating itself, the unexpected consequences that could come if an independent special counsel were named, and the difficulty of ferreting out leaks to the news media in a town built on the trading of information.

The controversy is over a flurry of stories that have revealed the Obama administration’s active role in clandestine operations against al-Qaeda and other adversaries.

They include the Associated Press’s reporting about a disrupted terrorist plot by al-Qaeda’s affiliate in Yemen, stories in several publications about the expanded U.S. drone campaign in Yemen and articles in the New York Times that described Obama’s role in approving “kill lists” for CIA drones and the use of computer viruses and cyberweapons against Iran.

Rogers, chairman of the House intelligence committee, said that in the absence of a special prosecutor more independent of Holder than the two U.S. attorneys, it will be important to learn whether Machen and Rosenstein have freedom to “go in following your leads where you find them, wherever that takes you.”

He added: “So many asked the question — me included — can you have a U.S. attorney assigned through the attorney general investigate something that is clearly going to be at the most senior levels of all of the executive branch, DoD [Defense Department] and FBI, the attorney general’s office and even the president?”

The intelligence committees are exploring whether new laws are warranted to criminalize leaks of national security information. But Rogers and Feinstein presented an understated and bipartisan response to what has become increasingly hot rhetoric regarding the leaks.

President Obama said on Friday that it was “offensive” to suggest that “my White House would purposely release classified national security information.”

Sen. John McCain (R-Ariz.), Obama’s 2008 opponent and his most outspoken critic on the issue, replied that it was the situation that was “offensive” and repeated his call for a special counsel to investigate.

“I mean, it’s obvious on its face that this information came from individuals who are in the administration,” McCain said on CNN’s “State of the Union.” Asked directly whether he believed Obama was responsible for release of the classified intelligence, McCain replied:

“I have no idea whether the president knew or did not know.” He added that “the president may not have done it himself, but the president is certainly responsible as commander in chief.”

The charge that the Obama administration would leak classified information to make the president look tough on terrorism is at odds with the White House’s record, said Obama political adviser David Axelrod, who also made the rounds of the Sunday talk shows.

Historically, there have been only nine serious leak investigations, and six of them are prosecutions brought by the Obama administration. “We have come under attack because we have been tougher on leaks than any administration in recent history,” Axelrod told George Stephanopoulos on ABC’s “This Week.”

Stephanopoulos pointed out that some of the sourcing in the stories was from the president’s national security team. But Axelrod said “the authors of all of this work have said the White House was not the source of this information. . . . There were obvious leaks, but they weren’t from the White House.”

Law enforcement sources say leak cases are particularly difficult because there are often hundreds of people who have had access to the classified material, including officials in the Justice Department, in the intelligence agencies and on Capitol Hill.

The widespread use of e-mail has made tracing the leaks easier, the sources said.

“Improved tools — including auditing measures, employee physical access or badging records, and phone records — play an important role in internal investigations and aid in unmasking individuals who leak classified information,” Lisa O. Monaco, assistant attorney general for the Justice Department’s national security division, said in Senate testimony in February.

Neither Feinstein nor Rogers were asked about new laws governing criminal prosecution of leaks. Leak prosecutions come under a 1917 espionage statute that criminalizes disclosure of national defense information that would be harmful to national interests.

Steven Aftergood, director of the Project on Government Secrecy with the Federation of American Scientists, noted that Attorney General John D. Ashcroft was asked by Congress in 2002 whether a new statute concerning leaks was needed, and he “more or less declined the offer.”

A new statute could categorically prohibit all unauthorized disclosures of classified information or impose greater sanctions on the media or surveillance of reporters, Aftergood said. But he added, “All of those are terrible ideas that would arouse significant opposition.”

Staff writers Sari Horwitz and Greg Miller contributed to this report.