Zumrati Juma had not heard from her 22-year-old son, Feroz Abbasi, for more than a year. She had checked with the police, the missing persons bureau, the mosque where he had worshiped -- all in vain, she recounted in an interview. By now she assumed he was dead, a careless young soul murdered for pocket change in London's back alleys.

Then last January a reporter from the British newspaper Sunday Times knocked on the door of her row house in South London with amazing news: Abbasi was alive and in the custody of the U.S. military at Guantanamo Bay, Cuba. He had been flown there in chains after being captured in Kunduz, Afghanistan, as a suspected al Qaeda foot soldier.

There he remains, nearly 10 months later, one of more than 600 men seized during U.S. military operations against al Qaeda and the Taliban who were declared illegal combatants with no right to lawyers, hearings or charges. And there, under U.S. policy, he will stay until Washington determines he is no longer a threat.

"At first I was so relieved that he was alive somewhere," Juma recalled. "But then I realized it's a complicated case and it's not going to be as simple as I thought. And it's 10 months now."

On Monday, a group of human rights lawyers will plead before the U.S. Court of Appeals for the District of Columbia Circuit on behalf of two Britons, two Australians and a dozen Kuwaitis for a writ of habeas corpus, a document that would require that they be produced in court, charged and tried -- or released. Whichever side wins, the next step will likely be an appeal to the Supreme Court.

But whatever the courts rule, the case of the Guantanamo detainees has already become a cause celebre for some foreign governments and human rights groups -- and an embarrassment for the State Department, which would like to see the Pentagon hasten the process of deciding who's a bona fide threat and who is innocent or harmless.

Canada, Germany, France, Denmark, Kuwait and Australia have all asked that their citizens be charged or released. The Inter-American Commission on Human Rights, an arm of the Organization of American States, has declared the United States in breach of its international obligations because it hasn't given detainees legal recourse.

Sergio Vieira de Mello, the United Nations' new high commissioner for human rights, said during a recent visit to London that the U.S. military's detainees should be taken before a court in the United States or their countries of origin. "Otherwise, they should be released," he said.

Even Britain, the United States' closest ally in the war on terrorism, is losing patience. There are seven Britons among the detainees, and while Prime Minister Tony Blair told a recent news conference that the detentions were necessary "at the moment," British officials have been quietly pressing their U.S. counterparts to speed up the process of determining which detainees can be released.

"It's still a hot issue here," said a senior British official who insisted on anonymity. "We've not said you must release all the British detainees, but we have asked the Americans to make decisions and sift out the small fry. If someone's not prosecutable, not of intelligence value and not a danger to society, he should be released."

In the United States, Yaser Esam Hamdi, a Louisiana-born man raised in Saudi Arabia, has sparked a parallel tug of war in the courts. He was captured in Afghanistan and is being held without access to lawyers in a Navy brig in Norfolk as an illegal enemy combatant. Lawyers arguing on his behalf contend that his Louisiana birth makes him a U.S. citizen entitled to legal counsel.

Last month, the Pentagon released three Afghans and a Pakistani from Guantanamo. Pentagon spokeswoman Victoria Clarke said more releases would eventually follow. "We have no desire to hold large numbers of these people for a long period of time," she said.

The U.S. Southern Command, which oversees the Guantanamo detention center, declined comment on Abbasi's case. Air Force Capt. Thomas Crosson said the command has a no-comment policy for all individual cases, under which the military would not confirm the identity of any particular detainee.

But as pieced together in Britain, Feroz Abbasi's story runs like this:

He was born in Uganda, came to Britain with his family when he was 8 and grew up in Croydon, a working-class community in South London. His mother works as a hospital nurse. His parents are Muslims, but his mother says neither is devout.

He was studying computer technology at a local college and living at home when he began to grow restless, his mother said. He took a trip to continental Europe, winding up in Geneva -- broke, lost and confused after he was robbed of all his money.

His mother sent him money to return home. He did, and later he told her that when he was feeling most desperate, he had experienced a religious awakening, inspired by a Kashmiri refugee who had told him, "If you believe in Allah, you'll find your way home."

After that, she recounted, her son began searching for religious instruction. He went to the local mosque but found it unrewarding. Then he made his way to the Finsbury Park mosque in northern London, and its charismatic preacher, Abu Hamza.

Hamza is a radical imam with hooks for hands, which he says were blown off during fighting against Soviet forces in Afghanistan. He is wanted for questioning in Yemen and Jordan for his alleged role in terrorist bombing campaigns there. He has expressed sympathy for Osama bin Laden, al Qaeda and the September 11, 2001, attacks, and authorities said he helped recruit hundreds of young Muslims for religious and military training in Afghanistan and Pakistan. British security authorities have kept him under surveillance but have not charged him. He denies any involvement in terrorism and told a public gathering in September that he cannot recall ever meeting Abbasi.

At first, Juma said, her son would venture up to Finsbury Park for Friday prayers. Then he started going up during the week for evening seminars. Then he moved into a dormitory there. He told her he was doing charitable work for Muslim refugees in Bosnia, but he was also serving as a security guard at the mosque and helping to set up an Internet site for Supporters of Shariah, a militant organization established by Hamza and other radicals. He would phone regularly to let Juma know where he was and when he would be coming home. Then, in December 2000, the phone calls suddenly stopped.

Juma said she went to Finsbury Park several times to search for her son. "They kept telling me to come back, they didn't know where he was," she recounted. She went to the authorities; she contacted the Pakistani Embassy and Pakistani airlines because she heard that young Muslims often journeyed to Pakistan for religious training. No one would help.

Then the Sunday Times reporter showed up at her door. "I almost fainted," she said. "They were the first people in a year to say to me, 'Your son is still alive.' "

But her relief soon turned to anxiety, she said, when British newspapers published photographs of the Guantanamo detainees bound, gagged and blindfolded. "Torture," declared one tabloid.

A British consular official was allowed to visit the detainees and reported back that the men were in good health and held under humane conditions. The official has returned three more times, accompanied each time by interrogators from MI5, the British internal security service. Louise Christian, a British lawyer whom Abbasi's family hired to try to represent him, said she learned through official channels that her client had demanded a lawyer at each of these sessions. The consular official passed on the request to U.S. authorities, who turned it down.

In April, the Sunday Times published what it called Abbasi's confession, in which he reportedly said that members of the Finsbury Park mosque had provided him with a plane ticket to Pakistan for military training at the Khaldan terrorist camp in Afghanistan. Abbasi also reportedly said that at one point that he wanted to become a suicide bomber and die as a martyr.

Christian was enraged by the report. If MI5 leaked the alleged confession, she said, "it's an extreme breach of privacy and abuse of their position by our own security services. He's had no access to a lawyer, he's not been charged with anything. Before being questioned by a police officer, he should have been given a long formal warning about incriminating himself."

Christian filed suit here to get the Foreign Office to intervene on Abbasi's behalf. A three-judge panel rejected the request this month, saying it could not require the Foreign Office to act but declaring that Abbasi's detention "appears to be a clear breach of a fundamental human right."

Recent terrorism attacks, however, such as the Oct. 12 bombing that killed almost 200 people in Bali, Indonesia, and Thursday's suicide bombing on a tourist hotel and almost simultaneous missile attack on an Israeli airliner in Mombasa, Kenya, may prolong the process. After the Bali attack, Prime Minister Blair told a news conference, "This terrorist threat is not over. . . . Some of the information that we are getting, it is important to relay back and interrogate and question those people who are still at Guantanamo Bay."

"The fact is, no one cares what happens to these people," said Michael Ratner, president of the Center for Constitutional Rights, the New York-based nonprofit litigation group that has brought the case to the federal appeals court. "They're in a legal black hole. But if a U.S. court doesn't have jurisdiction, then who does?"

Attorney Louise Christian, right, stands with Zumrati Juma, the mother of British citizen Feroz Abbasi, who was captured in Afghanistan and is now being held at a U.S. military detention camp in Guantanamo Bay, Cuba.