In May 2004, the White House dispatched the U.S. ambassador in Germany to pay an unusual visit to that country's interior minister. Ambassador Daniel R. Coats carried instructions from the State Department transmitted via the CIA's Berlin station because they were too sensitive and highly classified for regular diplomatic channels, according to several people with knowledge of the conversation.

Coats informed the German minister that the CIA had wrongfully imprisoned one of its citizens, Khaled Masri, for five months, and would soon release him, the sources said. There was also a request: that the German government not disclose what it had been told even if Masri went public. The U.S. officials feared exposure of a covert action program designed to capture terrorism suspects abroad and transfer them among countries, and possible legal challenges to the CIA from Masri and others with similar allegations.

The Masri case, with new details gleaned from interviews with current and former intelligence and diplomatic officials, offers a rare study of how pressure on the CIA to apprehend al Qaeda members after the Sept. 11, 2001, attacks has led in some instances to detention based on thin or speculative evidence. The case also shows how complicated it can be to correct errors in a system built and operated in secret.

The CIA, working with other intelligence agencies, has captured an estimated 3,000 people, including several key leaders of al Qaeda, in its campaign to dismantle terrorist networks. It is impossible to know, however, how many mistakes the CIA and its foreign partners have made.

Unlike the military's prison for terrorist suspects at Guantanamo Bay, Cuba -- where 180 prisoners have been freed after a review of their cases -- there is no tribunal or judge to check the evidence against those picked up by the CIA. The same bureaucracy that decides to capture and transfer a suspect for interrogation-- a process called "rendition" -- is also responsible for policing itself for errors.

The CIA inspector general is investigating a growing number of what it calls "erroneous renditions," according to several former and current intelligence officials.

One official said about three dozen names fall in that category; others believe it is fewer. The list includes several people whose identities were offered by al Qaeda figures during CIA interrogations, officials said. One turned out to be an innocent college professor who had given the al Qaeda member a bad grade, one official said.

"They picked up the wrong people, who had no information. In many, many cases there was only some vague association" with terrorism, one CIA officer said.

While the CIA admitted to Germany's then-Interior Minister Otto Schily that it had made a mistake, it has labored to keep the specifics of Masri's case from becoming public. As a German prosecutor works to verify or debunk Masri's claims of kidnapping and torture, the part of the German government that was informed of his ordeal has remained publicly silent. Masri's attorneys say they intend to file a lawsuit in U.S. courts this week.

Masri was held for five months largely because the head of the CIA's Counterterrorist Center's al Qaeda unit "believed he was someone else," one former CIA official said. "She didn't really know. She just had a hunch."

The CIA declined to comment for this article, as did Coats and a spokesman at the German Embassy in Washington. Schily did not respond to several requests for comment last week.

CIA officials stress that apprehensions and renditions are among the most sure-fire ways to take potential terrorists out of circulation quickly. In 2000, then-CIA Director George J. Tenet said that "renditions have shattered terrorist cells and networks, thwarted terrorist plans, and in some cases even prevented attacks from occurring."

After the September 2001 attacks, pressure to locate and nab potential terrorists, even in the most obscure parts of the world, bore down hard on one CIA office in particular, the Counterterrorist Center, or CTC, located until recently in the basement of one of the older buildings on the agency's sprawling headquarters compound. With operations officers and analysts sitting side by side, the idea was to act on tips and leads with dramatic speed.

The possibility of missing another attack loomed large. "Their logic was: If one of them gets loose and someone dies, we'll be held responsible," said one CIA officer, who, like others interviewed for this article, would speak only anonymously because of the secretive nature of the subject.

To carry out its mission, the CTC relies on its Rendition Group, made up of case officers, paramilitaries, analysts and psychologists. Their job is to figure out how to snatch someone off a city street, or a remote hillside, or a secluded corner of an airport where local authorities wait.

Members of the Rendition Group follow a simple but standard procedure: Dressed head to toe in black, including masks, they blindfold and cut the clothes off their new captives, then administer an enema and sleeping drugs. They outfit detainees in a diaper and jumpsuit for what can be a day-long trip. Their destinations: either a detention facility operated by cooperative countries in the Middle East and Central Asia, including Afghanistan, or one of the CIA's own covert prisons -- referred to in classified documents as "black sites," which at various times have been operated in eight countries, including several in Eastern Europe.

In the months after the Sept. 11 attacks, the CTC was the place to be for CIA officers wanting in on the fight. The staff ballooned from 300 to 1,200 nearly overnight.

"It was the Camelot of counterterrorism," a former counterterrorism official said. "We didn't have to mess with others -- and it was fun."

Thousands of tips and allegations about potential threats poured in after the attacks. Stung by the failure to detect the plot, CIA officers passed along every tidbit. The process of vetting and evaluating information suffered greatly, former and current intelligence officials said. "Whatever quality control mechanisms were in play on September 10th were eliminated on September 11th," a former senior intelligence official said.

J. Cofer Black, a professorial former spy who spent years chasing Osama bin Laden, was the CTC's director. With a flair for melodrama, Black had earned special access to the White House after he briefed President Bush on the CIA's war plan for Afghanistan.

Colleagues recall that he would return from the White House inspired and talking in missionary terms. Black, now in the private security business, declined to comment.

Some colleagues said his fervor was in line with the responsibility Bush bestowed on the CIA when he signed a top secret presidential finding six days after the 9/11 attacks. It authorized an unprecedented range of covert action, including lethal measures and renditions, disinformation campaigns and cyber attacks against the al Qaeda enemy, according to current and former intelligence officials. Black's attitude was exactly what some CIA officers believed was needed to get the job done.

Others criticized Black's CTC for embracing a "Hollywood model" of operations, as one former longtime CIA veteran called it, eschewing the hard work of recruiting agents and penetrating terrorist networks. Instead, the new approach was similar to the flashier paramilitary operations that had worked so well in Afghanistan, and played well at the White House, where the president was keeping a scorecard of captured or killed terrorists.

The person most often in the middle of arguments over whether to dispatch a rendition team was a former Soviet analyst with spiked hair that matched her in-your-face personality who heads the CTC's al Qaeda unit, according to a half-dozen CIA veterans who know her. Her name is being withheld because she is under cover.

She earned a reputation for being aggressive and confident, just the right quality, some colleagues thought, for a commander in the CIA's global war on terrorism. Others criticized her for being overzealous and too quick to order paramilitary action.

The CIA and Guantanamo Bay

One way the CIA has dealt with detainees it no longer wants to hold is to transfer them to the custody of the U.S. military at Guantanamo Bay, where defense authorities decide whether to keep or release them after a review.

About a dozen men have been transferred by the CIA to Guantanamo Bay, according to a Washington Post review of military tribunal testimony and other records. Some CIA officials have argued that the facility has become, as one former senior official put it, "a dumping ground" for CIA mistakes.

But several former intelligence officials dispute that and defend the transfer of CIA detainees to military custody. They acknowledged that some of those sent to Guantanamo Bay are prisoners who, after interrogation and review, turned out to have less valuable information than originally suspected. Still, they said, such prisoners are dangerous and would attack if given the chance.

Among those released from Guantanamo is Mamdouh Habib, an Egyptian-born Australian citizen, apprehended by a CIA team in Pakistan in October 2001, then sent to Egypt for interrogation, according to court papers. He has alleged that he was burned by cigarettes, given electric shocks and beaten by Egyptian captors. After six months, he was flown to Guantanamo Bay and let go earlier this year without being charged.

Another CIA former captive, according to declassified testimony from military tribunals and other records, is Mohamedou Oulad Slahi, a Mauritanian and former Canada resident, who says he turned himself in to the Mauritanian police 18 days after the 9/11 attacks because he heard the Americans were looking for him. The CIA took him to Jordan, where he spent eight months undergoing interrogation, according to his testimony, before being taken to Guantanamo Bay.

Another is Muhammad Saad Iqbal Madni, an Egyptian imprisoned by Indonesia authorities in January 2002 after he was heard talking -- he says jokingly -- about a new shoe bomb technology. He was flown to Egypt for interrogation and returned to CIA hands four months later, according to one former intelligence official. After being held for 13 months in Afghanistan, he was taken to Guantanamo Bay, according to his testimony.

The Masri Case

Khaled Masri came to the attention of Macedonian authorities on New Year's Eve 2003. Masri, an unemployed father of five living in Ulm, Germany, said he had gone by bus to Macedonia to blow off steam after a spat with his wife. He was taken off a bus at the Tabanovce border crossing by police because his name was similar to that of an associate of a 9/11 hijacker. The police drove him to Skopje, the capital, and put him in a motel room with darkened windows, he said in a recent telephone interview from Germany.

The police treated Masri firmly but cordially, asking about his passport, which they insisted was forged, about al Qaeda and about his hometown mosque, he said. When he pressed them to let him go, they displayed their pistols.

Unbeknown to Masri, the Macedonians had contacted the CIA station in Skopje. The station chief was on holiday. But the deputy chief, a junior officer, was excited about the catch and about being able to contribute to the counterterrorism fight, current and former intelligence officials familiar with the case said.

"The Skopje station really wanted a scalp because everyone wanted a part of the game," a CIA officer said. Because the European Division chief at headquarters was also on vacation, the deputy dealt directly with the CTC and the head of its al Qaeda unit.

In the first weeks of 2004, an argument arose over whether the CIA should take Masri from local authorities and remove him from the country for interrogation, a classic rendition operation.

The director of the al Qaeda unit supported that approach. She insisted he was probably a terrorist, and should be imprisoned and interrogated immediately.

Others were doubtful. They wanted to wait to see whether the passport was proved fraudulent. Beyond that, there was no evidence Masri was not who he claimed to be -- a German citizen of Arab descent traveling after a disagreement with his wife.

The unit's director won the argument. She ordered Masri captured and flown to a CIA prison in Afghanistan.

On the 23rd day of his motel captivity, the police videotaped Masri, then bundled him, handcuffed and blindfolded, into a van and drove to a closed-off building at the airport, Masri said. There, in silence, someone cut off his clothes. As they changed his blindfold, "I saw seven or eight men with black clothing and wearing masks," he later said in an interview. He said he was drugged to sleep for a long plane ride.

Afghanistan

Masri said his cell in Afghanistan was cold, dirty and in a cellar, with no light and one dirty cover for warmth. The first night he said he was kicked and beaten and warned by an interrogator: "You are here in a country where no one knows about you, in a country where there is no law. If you die, we will bury you, and no one will know."

Masri was guarded during the day by Afghans, he said. At night, men who sounded as if they spoke American-accented English showed up for the interrogation. Sometimes a man he believed was a doctor in a mask came to take photos, draw blood and collect a urine sample.

Back at the CTC, Masri's passport was given to the Office of Technical Services to analyze. By March, OTS had concluded the passport was genuine. The CIA had imprisoned the wrong man.

At the CIA, the question was: Now what? Some officials wanted to go directly to the German government; others did not. Someone suggested a reverse rendition: Return Masri to Macedonia and release him. "There wouldn't be a trace. No airplane tickets. Nothing. No one would believe him," one former official said. "There would be a bump in the press, but then it would be over."

Once the mistake reached Tenet, he laid out the options to his counterparts, including the idea of not telling the Germans. Condoleezza Rice, then Bush's national security adviser, and Deputy Secretary of State Richard L. Armitage argued they had to be told, a position Tenet took, according to one former intelligence official.

"You couldn't have the president lying to the German chancellor" should the issue come up, a government official involved in the matter said.

Senior State Department officials decided to approach Interior Minister Schily, who had been a steadfast Bush supporter even when differences over the Iraq war strained ties between the two countries. Ambassador Coats had excellent rapport with Schily.

The CIA argued for minimal disclosure of information. The State Department insisted on a truthful, complete statement. The two agencies quibbled over whether it should include an apology, according to officials.

Meanwhile, Masri was growing desperate. There were rumors that a prisoner had died under torture. Masri could not answer most questions put to him. He said he steadied himself by talking with other prisoners and reading the Koran.

A week before his release in late May 2004, Masri said he was visited in prison by a German man with a goatee who called himself Sam. Masri said he asked him if he were from the German government and whether the government knew he was there. Sam said he could not answer either question.

"Does my wife at least know I'm here?" Masri asked.

"No, she does not," Sam replied, according to Masri.

Sam told Masri he was going to be released soon but that he would not receive any documents or papers confirming his ordeal. The Americans would never admit they had taken him prisoner, Sam added, according to Masri.

On the day of his release, the prison's director, who Masri believed was an American, told Masri that he had been held because he "had a suspicious name," Masri said in an interview.

Several intelligence and diplomatic officials said Macedonia did not want the CIA to bring Masri back inside the country, so the agency arranged for him to be flown to Albania. Masri said he was taken to a narrow country road at dusk. When they let him off, "They asked me not to look back when I started walking," Masri said. "I was afraid they would shoot me in the back."

He said he was quickly met by three armed men. They drove all night, arriving in the morning at Mother Teresa Airport in Tirana. Masri said he was escorted onto the plane, past all the security checkpoints, by an Albanian.

Masri has been reunited with his children and wife, who had moved the family to Lebanon because she did not know where her husband was. Unemployed and lonely, Masri says neither his German nor Arab friends dare associate with him because of the publicity.

Meanwhile, a German prosecutor continues to work Masri's case. A Macedonia bus driver has confirmed that Masri was taken away by border guards on the date he gave investigators. A forensic analysis of Masri's hair showed he was malnourished during the period he says he was in the prison. Flight logs show a plane registered to a CIA front company flew out of Macedonia on the day Masri says he went to Afghanistan.

Masri can find few words to explain his ordeal. "I have very bad feelings" about the United States, he said. "I think it's just like in the Arab countries: arresting people, treating them inhumanly and less than that, and with no rights and no laws."

Staff researcher Julie Tate contributed to this article.

Commentary:
The first case of illegal rendering I recorded was a Canadian citisen who was sent to Syria and tortured for month, then returned after they found it was all a mistake. For more US sends Canadian to Syria to be tortured

April 22, 2004: The Canadian who was deported from the U.S. to Syria, where he says he was tortured as a suspected terrorist, is looking for compensation.

Arar, a Syrian-born Canadian citizen with dual citizenship, was detained by U.S. officials in September 2002 during a stopover in New York. He was on his way home to Canada from a trip to Tunisia.

On Oct. 8, he was flown to Jordan and then transported to Syria, where he says he spent close to 10 months being tortured.

Arar, who has denied being a terrorist and has not been charged with a crime, was eventually released and later returned to Canada.