Three British subjects alleged Wednesday that they were beaten, shackled in painful positions, deprived of sleep and subjected to continual humiliation while held for more than two years at the U.S. detention camp at Guantanamo Bay, Cuba.

The allegations by the three men, captured in Afghanistan after the fall of the Taliban government in November 2001, were made in a 115-page report compiled and released by their attorneys. There was no independent verification of the reports, and the men were not available for comment. In the past, they have given interviews to news media only in return for payment.

The men, who were released in March, asserted that they also were forcibly injected with drugs, exposed to intense heat and cold and pressured to make false confessions. They said other detainees were brutally beaten and attacked by dogs.

"All of the techniques they describe are illegal and a violation of the Geneva Conventions, and cumulatively they amount to torture," said Michael Ratner, president of the Center for Constitutional Rights in New York, which has represented the men and others detained by the United States.

The U.S. military denied the allegations. "The claim that detainees have been physically abused, beaten or tortured is simply not true," said Army Col. David McWilliams, spokesman for the U.S. Southern Command, which is in charge of the prison. "From the beginning we have taken extra steps to treat prisoners not only humanely but extra cautiously. We do not use any kind of coercive or physically harmful techniques."

The men -- Shafiq Rasul, 27, and Asif Iqbal and Rhuhel Ahmed, both 22 -- are Muslims from the city of Tipton in central England. Their claims followed similar allegations of prisoner abuse against U.S. military guards at Abu Ghraib prison in Iraq and at several holding facilities in Afghanistan.

The men did not explain in the report why they were in Afghanistan, although in the past they claimed to have gone for humanitarian reasons while visiting Pakistan.

U.S. Embassy press attache Lee McClenny cited a letter he had sent to a British newspaper this year alleging that the men had been trained to use military weapons and had fought for the Taliban in Afghanistan.

In their report, the men described their detention by anti-Taliban Afghan forces in late November 2001. They said they were held for about a month and then transferred to the custody of U.S. forces in Kandahar, Afghanistan. They said they were also beaten and abused during interrogations there before being sent by plane to Guantanamo.

In Guantanamo, the men said, they were frequently stripped, subjected to anal cavity searches and threatened with death.

Their treatment grew worse, they said, after the arrival of Maj. Gen. Geoffrey D. Miller as camp commander in fall 2002. Miller eventually became commander of military prisons in Iraq.

"That is when short-shackling started, loud music playing in interrogation, shaving beards and hair, putting people in cells naked, depriving them of sleep," Rasul said. The report said interrogators insisted that the men confess to being fighters for the Taliban or al Qaeda. But once they agreed, they said, interrogators tried to force them into more false confessions. Rasul said he eventually agreed that he had met in 2000 with Osama bin Laden and Mohamed Atta, leader of the hijackers who attacked New York and the Pentagon on Sept. 11, 2001. But he said he actually was working at the time for a discount appliance store in Tipton.

"I was going out of my mind and didn't know what was going on," Rasul said in the report. "I was desperate for it to end."

McWilliams, the Army spokesman, said interrogators had avoided coercive techniques and instead used strategies that did not rely on physical abuse. Contrary to the men's accounts, conditions improved after Miller took over, he said.

Methods outlined in report "amount to torture," said Michael Ratner of the Center for Constitutional Rights.