The U.S. Senate has voted down a measure calling for an independent inquiry into U.S. military interrogation practices of detainees in the war on terrorism.

By a 43 to 55 vote, the Republican-led Senate turned down a Democrat-sponsored amendment to the defense authorization bill that would have established an independent commission to investigate U.S. military interrogation practices. The commission would have been modeled after the inquiry into the September 11, 2001 terrorist attacks.

Senator Jay Rockefeller of West Virginia, the top Democrat on the Senate Intelligence Committee, wanted the probe to look at, among other things, the U.S. practice of sending detainees to foreign governments for interrogation, known as rendition. "There have been numerous reports where individuals turned over by the United States to a foreign government for interrogation for allegedly doing torture. In addition to the ethical and legal considerations associated with this practice, the veracity of the information gained from these and other detainees is called into question if these statements were gained under physical coercion."

Senator Carl Levin, the top Democrat on the Senate Armed Services Committee, said an independent probe would help restore the U.S. image in the world after last year's prisoner abuse scandal. Photographs of American troops abusing or mistreating detainees at the Abu Ghraib prison in Iraq shocked the world. "We need a 9-11 type commission to restore credibility to this nation. It is important to our troops so that confidence in America in the way we deal with people we capture and detain can be restored in the world. We need the support of people around the world in our war on terrorism."

But the Armed Services Committee chairman, Republican Senator John Warner of Virginia, said the Bush administration is already taking steps to address the issue, noting that the Defense Department has issued a directive aimed at strengthening the rules against the abuse of detainees during interrogations. The directive underscores that all detained personnel shall be treated humanely and that acts of physical and mental torture are prohibited. It specifically bans the use of dogs to intimidate detainees.

Senator Warner underscored his opposition to the Democrats' amendment. "An independent commission would send, potentially, the wrong message to our armed forces of our lack of confidence in their conduct, and would seriously undermine ongoing intelligence gathering activities."

Senator Warner said there already has been a number of investigations into detainee interrogation practices.

But Senator Levin said previous inquiries have not dealt with the CIA's role. "There has been no look at the intelligence community's participation in interrogation of detainees," he said.

The congressional debate came in the aftermath of a Washington Post newspaper report alleging secret Central Intelligence Agency prisons in Eastern Europe for terrorism suspects. The Bush administration has neither confirmed nor denied the report.

Senate Majority Leader Bill Frist and House Speaker Dennis Hastert are reported to be circulating a letter calling for a congressional probe into the disclosure of the covert interrogation centers.

The Senate last month voted to limit the military's interrogation and detention tactics to those described in the Army Field Manual, and prohibit all U.S. government employees from using cruel, inhuman or degrading treatment.

The fate of that amendment - contained in a separate Senate defense spending bill, but not in the House version of the legislation - depends on negotiations to reconcile differences in the two measures.