Chief U.S. District Judge John W. Bissell granted a preliminary injunction in the case Wednesday, ruling that such hearings may only be closed on a case-by-case basis by the judge conducting the proceeding.
Civil rights groups and two newspapers had requested the injunction.
In a Sept. 21 memorandum, the nation's chief immigration judge directed immigration judges to close hearings involving detainees whose cases have been designated of "special interest" to the FBI. The memo also prohibited court administrators from listing the cases on dockets, or confirming when hearings are to be held.
"Without an injunction, the government could continue to bar the public and press from deportation proceedings without any particularized showing of justification. This presents a clear case of irreparable harm to a right protected by the First Amendment," Bissell wrote.
The Justice Department has not decided whether to appeal, spokesman Charles Miller said.
In a statement, the department said: "The closure of these hearings is vital to the ongoing efforts of law enforcement to take reasonable but necessary steps to protect our national security."
As of Wednesday, 104 post-Sept. 11 detainees were in custody around the nation, down from more than 700, Justice Department spokesman Dan Nelson said. Most have been held in county jails in New Jersey. It was unclear how many have been deported.
In another case in Washington, civil rights and public access groups told a federal judge Wednesday that the Justice Department is ignoring fundamental freedom of information laws by keeping secret the names of those detained as part of the Sept. 11 investigation.
The case will likely decide how much the government can keep secret in its effort to capture terrorists. U.S. District Court Judge Gladys Kessler did not say when she would rule on the complaint.
In New Jersey, Bissell acted on a lawsuit that was filed March 6 by the Newark chapter of the American Civil Liberties Union and the New York-based Center For Constitutional Rights on behalf of the New Jersey Law Journal, a weekly publication, and North Jersey Media Group, publisher of the Herald News of West Paterson, a daily newspaper.
The newspapers' reporters tried to cover court hearings involving detainees, but were barred from courtrooms, along with the rest of the public.
"As important as the war on terrorism is, it doesn't supersede our constitutional rights," Lawrence Lustberg, a lawyer for the newspapers, said Wednesday.
By Jeffrey Gold