More cases of possible mistreatment of Iraqi prisoners have come to Congress' attention and need investigation by the Pentagon, the chairman of the Senate Armed Services Committee (search) said Thursday.

Sen. John Warner, R-Va., also said that L. Paul Bremer (search), the former head of the American-led occupation in Iraq, may testify about prison abuse at a congressional hearing next week.

"I'm not trying to, you know, drop a little hint here. I'm just saying ... each day that comes along, new incidents that occurred in the past" are revealed and will need to be investigated, Warner said.

Despite a number of hearings and media revelations in the months since the abuse scandal broke, questions linger about the extent of wrongdoing at U.S. military prisons, how it happened and who should be held accountable.

Before the Senate goes into recess next week, Warner wants Bremer to testify at a public hearing.

Warner spoke to reporters after his committee had a private, classified briefing on the status of several Defense Department (search) investigations into abuse stand. He gave no further details on what new allegations came up during the briefing.

But just this week, the Red Cross (search) said the United States might be hiding detainees in lockups around the world that the group's representatives have not visited.

The Pentagon denies the charge. The CIA has declined comment on whether it may be holding terrorism suspects at foreign locations.

The scandal began unfolding with the release of pictures from mistreatment of prisoners at Iraq's Abu Ghraib (search) prison. Questions have arisen about prisons in Afghanistan and Guantanamo Bay, Cuba, and the deaths of detainees, as well as whether abuse was part of interrogations.

Also, Bush administration memos seemed to indicate that officials had condoned or approved the use of torture.

Since the disclosures, victims have filed lawsuits and an American contractor Nick Berg was beheaded in Iraq in May, purportedly in retribution for the abuse. U.S. officials have acknowledged that the scandal has diminished America's standing in the world.

The abuse forced the United States last month to back off an effort to continue an exemption that American soldiers had from international prosecution for war crimes.

Warner has held three public hearings of his committee since May, summoning Defense Secretary Donald H. Rumsfeld and other Pentagon officials to testify. For more than a month, Warner set the issue aside as he worked on passing defense spending legislation.

But now, the possibility of hearings with people who know what happened has diminished because of current criminal investigations, Warner said.

"We cannot in any way jeopardize the rights of individuals being investigated," the senator said.

"And consequently, we cannot, at this time, bring them before the committee," he said.

In addition to investigating the allegations of abuse at its facilities in Iraq and Afghanistan, the Pentagon is assessing interrogation techniques used in the fight against terrorism and procedures used at Abu Ghraib by military intelligence and contractors.