Mohammed al-Qahtani, detainee No. 063, was forced to wear a bra. He had a thong placed on his head. He was massaged by a female interrogator who straddled him like a lap dancer. He was told that his mother and sisters were whores. He was told that other detainees knew he was gay. He was forced to dance with a male interrogator. He was strip-searched in front of women. He was led on a leash and forced to perform dog tricks. He was doused with water. He was prevented from praying. He was forced to watch as an interrogator squatted over his Koran.

That much is known. These details were among the findings of the U.S. Army’s investigation of al-Qahtani's aggressive interrogation at Guantanamo Bay, Cuba.

But only now is a picture emerging of how the interrogation policy developed, and the battle that law enforcement agents waged, inside Guantanamo and in the offices of the Pentagon, against harsh treatment of al-Qahtani and other detainees by military intelligence interrogators.

In interviews with MSNBC.com — the first time they have spoken publicly — former senior law enforcement agents described their attempts to stop the abusive interrogations. The agents of the Pentagon's Criminal Investigation Task Force, working to build legal cases against suspected terrorists, said they objected to coercive tactics used by a separate team of intelligence interrogators soon after Guantanamo's prison camp opened in early 2002. They ultimately carried their battle up to the office of Secretary of Defense Donald H. Rumsfeld, who approved the more aggressive techniques to be used on al-Qahtani and others.

Although they believed the abusive techniques were probably illegal, the Pentagon cops said their objection was practical. They argued that abusive interrogations were not likely to produce truthful information, either for preventing more al-Qaida attacks or prosecuting terrorists.

And they described their disappointment when military prosecutors told them not to worry about making a criminal case against al-Qahtani, the suspected "20th hijacker" of Sept. 11, because what had been done to him would prevent him from ever being put on trial.

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When Gen. Geoffrey D. Miller, the U.S. Army general in charge of detainees at Guantanamo Bay, flew to Iraq on Aug. 31, 2003, to advise on operation of a little-known prison called Abu Ghraib, his plane also carried something of a stowaway.

An agent of the Pentagon’s Criminal Investigation Task Force went along to warn U.S. prison officials in Iraq that Gen. Miller’s aggressive interrogation techniques were not the only way, that there were legal and effective ways of building rapport with detainees to get them to talk.

The task force’s top cop, Mark Fallon, had sent the agent. Fallon said he feared that the Guantanamo techniques would spread.

"I wanted to tackle the general, anything to stop him from getting on that plane," Fallon said. "The best I could do was to send along a chaperone."

Gen. Miller resisted the agent, Blaine Thomas, joining his team, according to Fallon and his commander, Col. Brittain P. Mallow. He eventually relented, they said, but in Iraq he told the agent three times that he wasn't needed in meetings. So the agent made the best of his time in Iraq, meeting with the FBI.

The general, now retired, says the cops have it backward. "I’m the one who asked their guy to come" on the Abu Ghraib trip, Gen. Miller said, "and when they sent him, he was the one who decided to work with the FBI and other agencies instead of coming to the briefings. He had free and open access like everyone else."

In early April 2004, Gen. Miller left Guantanamo for a new role, running all U.S. prisons in Iraq, a few weeks before the name Abu Ghraib became well known. An Army investigation found later that Miller on his first visit had urged that military police with dogs "set the conditions" for interrogations, and that interrogators adopt "emerging strategic interrogation strategies and techniques" being used at Guantanamo.

"When the Abu Ghraib photos were released," Fallon said, "I felt a great disappointment."

"I wasn’t there for the meetings with General Miller. I do not know what he told those folks over there, what techniques to employ. ... But I felt a great sense of disappointment that I was not able to effectively influence behaviors that could have contributed to Abu Ghraib."

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At Orlando International Airport on Aug. 4, 2001, a Saudi traveler caught the eye of a Customs agent.

The young man had no return ticket, $2,800 in cash, and wouldn’t identify the friend he said would pick him up at the airport. The Customs agent decided this was a potential illegal immigrant. Before being sent on a flight back to the Middle East, Mohammed al-Qahtani turned to the agent and said, "I’ll be back."

The Pentagon has said that his friend at the airport was the Sept. 11 ringleader, Mohammed Atta, and that al-Qahtani was apparently intended to be the fifth hijacker on United Airlines Flight 93, which crashed in Pennsylvania when passengers were able to overpower the other four. Al-Qahtani, through his attorney, says he was not involved.

Al-Qahtani was captured in December 2001 on the Afghanistan-Pakistan border and shipped to the U.S. prison camp at Guantanamo Bay.

For awhile he cooperated with FBI interrogators, but by the fall of 2002, he had mostly stopped talking.

The pressure on interrogators to produce information was intense. Less than a year after the Sept. 11 attacks, al-Qaida attacks were continuing: the firebombing of a synagogue in Tunisia in April, a bomb outside the U.S. Consulate in Karachi in June.

In early September 2002, the FBI suggested another option for obtaining information from al-Qahtani, according to the leaders of the law enforcement task force, who shared an office at Guantanamo with the FBI. The plan, they said, was to send al-Qahtani temporarily or permanently to another country, such as Egypt or Jordan, where he could be interrogated with techniques that the FBI could not legally use.

The commander of the law enforcement task force, Col. Britt Mallow, and his chief investigator, Mark Fallon, say they learned of the plan from the Pentagon’s Office of General Counsel, which urged them to reach a consensus with the FBI and intelligence interrogators on how to handle al-Qahtani. The cops opposed the plan, which was scrapped. A later FBI legal analysis warned that even discussing such a plan, known as "rendition," could be a crime, conspiracy to commit torture.