Democratic congressional leaders welcomed the call for an investigation, but said it should be broader than the possible leak about the prison system.
In a statement, Senate Minority Leader Harry Reid (D-Nev.) condemned leaking as unacceptable, but added: "While Republicans have been quick to call for an investigation of this matter, they have repeatedly and regularly resisted any real oversight of this administration's flawed policies."
House Minority Leader Nancy Pelosi (D-San Francisco) said that "if Speaker Hastert and Majority Leader Frist are finally ready to join Democrats' demands for an investigation of possible abuses of classified information, they must direct the House and Senate intelligence committees to investigate all aspects of that issue."
At least one Senate Republican agreed. Asked whether he thought there should be a probe of the existence of the prisons, or of the leak of classified information about them, Sen. Lindsey Graham of South Carolina rolled his eyes and replied: "How about both? I'd like to know why we've got secret prisons and what oversight precautions we have."
It is "imperative we regain the moral high ground," he said. "And having secret prisons come out in the Washington Post is not a good way to regain it."
Another Republican, Sen. Trent Lott of Mississippi, said that senators from his party might have given information to the Post. Lott told reporters that the existence of the prison system was discussed last week at the Republican policy luncheon on Capitol Hill, which was attended by Vice President Dick Cheney and held the day before the Post published its report.
"Information that was said in there, given out in there, did get into the newspaper," Lott said. "I don't know where else it came from.... It looked to me that at least one of those reports came right out of that room."
In their letter, Frist and Hastert said the panels should determine whether the Post's information was accurate, who leaked it and "what is the actual and potential damage done to the national security of the United States and our partners in the global war on terror."
"The leaking of classified information by employees of the United States government appears to have increased in recent years," they said, "establishing a dangerous trend that, if not addressed swiftly and firmly, likely will worsen."
Times staff writers Greg Miller and Maura Reynolds contributed to this report.
