U.S. officials insist that detainees are treated and interrogated humanely at Guantanamo and that any abuse is immediately reported and punished. Nonetheless, news of the existence of the tapes raises the prospect of more images of alleged U.S. brutality emerging, broadening and deepening the scandal over what Secretary of Defense Donald Rumsfeld called the "radioactive" pictures of detainees being abused at the now twice-notorious Abu Ghraib prison complex in Iraq.

One set of the Guantanamo allegations centers on the actions of the Immediate Response Force, a special team of guards tasked to deal with detainee misconduct and violence. In recent media interviews and letters to U.S. senators, three Britons who were held at the camp until their release in March 2004 described several incidents in which they say the team savagely assaulted inmates.

"They pepper-sprayed me in the face. ... They tied me up like a beast and then they were kneeling on me, kicking and punching," Tarek Dergoul, one of the three, told the Observer newspaper in London Sunday.

The allegations were dismissed by the Pentagon Wednesday. "These accounts are not credible," a Defense Department official who asked not to be named told UPI. "If they were credible, they would have been investigated and the perpetrators punished."

Lt. Col. Leon H. Sumpter, the spokesman for the Joint Task Force that runs Camp Delta, the detention and interrogation center at Guantanamo, confirmed to UPI that all the interventions by the special team were videotaped "to ensure that only the minimum force necessary is employed."

He added in an e-mail message that the teams -- which receive "specialized training on how to ... use the minimum force necessary to overcome the misconduct" -- know they are being filmed.

Sumpter said that Naval Inspector General Vice Adm. Albert T. "Tom" Church had reviewed several of the tapes during a visit to the base earlier this month and had taken some of them away with him.

At a subsequent media briefing, Church stressed that his two-day visit was a review, not an inspection, and that "you can't be 100 percent confident of what your findings are when you have that little time to do the job."

Church said that he was aware of eight incidents over the past two years, including one in which a detainee was assaulted after he had been subdued by the IRF team. All had been reported up the chain of command and swiftly dealt with in proper fashion, he said. None approached the level of violence described by the three former detainees.

He said he had urged Rumsfeld to follow up his brief visit by looking in more detail at some issues raised by the Red Cross and by "reaching back" to interview personnel who were stationed at the base prior to the current team being deployed nine or 10 months ago.

The tapes have also been requested by senators seeking to resolve the lingering questions about how widespread the kind of abuse seen at Abu Ghraib is.

"These tapes may help resolve some of the uncertainties about these allegations," said an aide to Sen. Patrick Leahy, D-Vt., who requested the tapes in a letter to Rumsfeld on Monday. Sumpter said that he had no information about the request, but the task force would always "comply fully with all authorized requests."

"If the incidents described (by Dergoul and the others) really happened, it suggests that some of the same cruel and degrading treatment that we know about at Abu Ghraib also happened at Guantanamo," the aide said. "That would suggest that it was much more pervasive than the administration has acknowledged."

Lawyers for the three men say the same techniques of stress and duress and sexual humiliation revealed by the pictures from Abu Ghraib were used at Guantanamo.

Barbara Olshansky, assistant legal director of the New York-based Center for Constitutional Rights, represents two other British ex-detainees, Shafiq Rasul and Asif Iqbal. She said last week that her clients were often taunted by female personnel and menaced by dogs while being held naked in the same way the notorious pictures from Abu Ghraib show detainees there being treated.

Olshansky said the men's treatment was a matter of "the policy of the American military in handling all these situations." Of the men's treatment at Guantanamo Bay, she said, "It appeared to them that this was the routine."

Olshansky suggested that there was a lot more photographic material at Guantanamo than just that of the incidents involving the IRF teams.