The inner-workings of the FBI's Carnivore e-mail snooping system will remain secret, at least for now, despite a privacy rights group's request for immediate information.

In an emergency hearing on Wednesday, a federal judge rejected the request from the Electronic Privacy Information Center (EPIC) to fast-track its July Freedom of Information Act query about the surveillance system. Instead, the judge ordered the FBI to report back in 10 days on its progress in reviewing the query.

EPIC, in its application to the judge, accused the FBI and the U.S. Justice Department of breaching the law by failing to act on the request to speed-up the process.

In July, the FBI told Congress that Carnivore is designed to intercept data from the electronic mail of a criminal suspect by monitoring traffic at an Internet service provider. EPIC wants the FBI to disclose how it works.

U.S. District Judge James Robertson held the hearing at 3:30 p.m. at the federal courthouse in Washington.

Attorney General Janet Reno said last week that technical specifications of the system will be disclosed to a "group of experts."

In an open letter, 27 House Republicans and one Democrat urged Reno last week to suspend use of Carnivore until the privacy issues it raised were resolved.

"People should feel secure that the federal government is not reading their e-mail, no matter how worthy the objective," House Republican leader Rep. Dick Armey of Texas and co-signers wrote.

The FBI had no immediate comment on the emergency hearing. The Justice Department did not immediately respond to requests for comment on the move to compel release of "all records" on Carnivore. The American Civil Liberties has also filed a FOIA request for details on Carnivore, including the software code.

The FBI has likened the system to a traditional wiretap in that both require a court finding of probable cause before surveillance may be undertaken.

At least three bills have been introduced in Congress that would clarify legal standards applying to interception of e-mail.

David Sobel, general counsel of the Washington-based privacy center known by its acronym EPIC, said there was no substitute for a full and open public review of the Carnivore system.

"Unless the public gets access to relevant information, we will not have a fully informed debate on these issues," he said in a telephone interview.

EPIC filed its initial FOIA request on July 12. Six days later it asked the Justice Department to expedite the pending query on the ground that it had become a matter of exceptional news media concern raising questions about "the government's integrity which affect public confidence" — one of the legal standards that qualifies a request for "expedited processing."

Despite a 10-day statutory time limit to answer requests for accelerated processing, Sobel said the Justice Department failed to respond to EPIC's request. The 10 days ran out on Friday, he said.

"If there was ever a request that qualified for expedited treatment, this is it," Sobel added.

Although Carnivore reportedly "sniffs" or scans all traffic at an Internet Service Provider once it is installed by court order, the FBI says only the data or messages relevant to a criminal investigation get stored and reviewed.

All other information it sifts through is discarded, Donald Kerr, director of the FBI lab that developed Carnivore, told Congress at a July 24 hearing.

Some lawmakers suggested the tool may infringe on the Fourth Amendment to the Constitution, which protects Americans from unreasonable search and seizure.

— Fox News' Brian Sierra and Patrick Riley, and Reuters contributed to this report