ASHINGTON, Jan. 4 — A coalition of news and legal organizations is seeking public access to information about a post-Sept. 11 detention case now before the Supreme Court that has been handled with unusual secrecy both there and in the lower federal courts.

The case, which the justices have not yet agreed to review, is an appeal filed by the Federal Public Defender's office in Miami on behalf of Mohamed Kamel Bellahouel, an Algerian-born resident of South Florida and one of more than 1,000 Arab men swept up and imprisoned following the terrorist attacks of 2001.

Because all the lower-court records, including the actual decisions, are sealed, there is little public information about the case, M.K.B. v. Warden, No. 03-6747. It was filed at the Supreme Court in June using only Mr. Bellahouel's initials.

A brief to be filed at the court on Monday by the Reporters Committee for Freedom of the Press on behalf of 23 media organizations and other groups, including the American Immigration Lawyers Association, requests the court's permission to intervene in the case.

If granted, the unusual request would give the organizations — which include The New York Times, The Washington Post and CNN — the status of parties, with a direct stake in the outcome, rather than simply "friends of the court." Their brief tells the court that they would then argue that all information about the case should be made public except for material that is classified or "truly required for national security purposes" to be kept secret.

Much of the information available now comes from a series of articles in The Miami Daily Business Review, which learned about the case in March when it was pending before the United States Court of Appeals for the 11th Circuit, in Atlanta. The clerk's office of the appeals court inadvertently and briefly listed the case on a public docket. Previously, not even the existence of the case had been made public.

The publicly available version of the Supreme Court petition omits many details, including even the identities of the lower courts, and includes blank pages. The justices received complete versions.

After Solicitor General Theodore B. Olson told the court that the government would have no response to the petition, the court directed the government to respond.

Mr. Olson's brief is due at the court on Monday. It is likely that none or at most a small part of the brief will be publicly available.

Mr. Bellahouel worked as a waiter in a restaurant in Delray Beach, Fla., that the Federal Bureau of Investigation says was patronized by at least two Sept. 11 hijackers, Mohamed Atta and Marwan al-Shehhi.

During his five-month imprisonment at the Krome Detention Center in Miami, Mr. Bellahouel was taken to Alexandria, Va., to testify before the grand jury that was investigating Zacarias Moussaoui.

The government has not charged Mr. Bellahouel with any terrorism-related crimes and apparently does not regard him as a threat. He has been free on a $10,000 immigration bond since March 2002 and faces possible deportation for having overstayed the student visa on which he entered the country to attend Florida Atlantic University in 1996. His wife is a United States citizen.

While in custody, Mr. Bellahouel sought release through a petition for a writ of habeas corpus filed in Federal District Court in Miami. Judge Paul C. Huck closed all proceedings in the case, which was never listed on the court's public docket. The 11th Circuit then maintained the secrecy, holding an argument behind closed doors last March 5 and issuing its decision under seal on March 31.

For that reason, the substance of the case remains publicly unknown. The question that Kathleen M. Williams and Paul M. Rashkind of the Federal Public Defender's office in Miami have brought to the Supreme Court, at least in the public part of their filing, is whether the lower courts "failed to comply with the court's common-law and First Amendment jurisprudence governing public access to court filings and proceedings" by cloaking the entire case in secrecy without justifying the need to do so.

"Although the right to access is not absolute, the right of the public to litigate its entitlement to access must be absolute if the public is to have means to effect its right of access," the petition asserts.

The Reporters Committee request to intervene asserts that the media organizations' "strong First Amendment interests may not be adequately represented" by Mr. Bellahouel because, given his immigration situation, he may be motivated to settle the case rather than press the public-access argument.