MIAMI — In a reversal, the Justice Department has acknowledged in a Miami federal court filing that it must notify defendants in terrorism cases if evidence from once-secret government surveillance programs will be used against them.

Criminal defendants are generally entitled to know in advance the evidence used to prosecute them. But in a case involving two Pakistani-born brothers accused of plotting to bomb New York City, federal prosecutors insisted in May they were not required to disclose any role played by the broad surveillance. The programs include the National Security Agency phone and Internet surveillance revealed by leaker Edward Snowden.

In the filing Tuesday, however, Assistant U.S. Attorney Karen Gilbert said the Justice Department would "provide notice to the defense and this court if the government intended to use in this case any information obtained or derived" from the surveillance programs. She added that no notice will be provided, however, because prosecutors don't intend to use such evidence against Raees and Sheheryar Alam Qazi.

As for the previous filing asserting no notice was required, Gilbert said, "that is not the government's position." The shift was first reported by The Wall Street Journal.

The Qazi brothers have pleaded not guilty to several terrorism-related charges stemming from an alleged plot to attack New York landmarks to avenge deaths in Afghanistan from U.S. drone attacks. Key evidence against them was produced under the Foreign Intelligence Surveillance Act, under which a secret court has authorized the sweeping phone and Internet surveillance programs recently brought to light by Snowden, a former NSA contractor.

Karen Greenberg, director of the Center on National Security at Fordham University Law School, said Wednesday the about-face was inevitable, but hastened by the publicity surrounding Snowden's disclosures.

"I think this was probably going to happen anyway, but I think the timing is probably because this has been forced into the national arena," she said. "We'll see how this plays out in terms of what actually happens in court. It's a good intention, a step forward in terms of transparency."

The law has long required notice to defendants when evidence from FISA warrants — phone wiretaps, Internet surveillance and so forth — is to be used against them, giving them a chance to challenge it.

Lawyers for the Qazi brothers wanted the underlying information used to obtain those warrants from the secret Foreign Intelligence Surveillance Court. That might include phone numbers associated with the Qazis that were swept up by the NSA, which the government would then use to get warrants for such investigative tools as phone wiretaps.

It was this information the government had resisted revealing, because it would disclose intelligence gathering methods. Now, those methods are becoming publicly known anyway.

"It is a logical step forward because of the constitutional rights afforded a defendant in a criminal trial," said Scott Silliman, a law professor and director emeritus at Duke University's Center on Law, Ethics and National Security.

Lawyers for the Qazi brothers have sought to have evidence obtained under FISA thrown out and to have the entire law declared unconstitutional. Prosecutors want U.S. District Judge Robert Scola, who is presiding over the case, to examine the FISA-related evidence in private and not hold a public court hearing because it "would harm the national security of the United States," according to court documents.

Scola has not yet ruled on those motions.