Court documents and FBI field reports reviewed by ABC News undercut and contradict the dramatic testimony from senior counter-terrorism officials that the National Security Agency's surveillance programs thwarted an attack by al Qaeda on the New York Stock Exchange.
According to an FBI interview with an imprisoned al Qaeda figure involved in the plot, "there was no further operational planning of that target" after surveillance found the four streets around the exchange building "were blocked off from vehicular traffic."
The FBI document was filed last month in federal court in New York as part of the government sentencing memorandum for one of the alleged plotters, Sabirhan Hasanoff, who is to be sentenced next week.
But the FBI deputy director, Sean Joyce, provided Congress with a different version of events Tuesday as he cited the stock exchange plot as one of more than 50 "terror events" that had been disrupted with the help of the NSA's secret surveillance programs.
"We went up on the electronic surveillance and identified his co-conspirators and this was the plot that was in the very initial stages of plotting to bomb the New York Stock Exchange," Joyce testified.
Asked whether it was a "serious plot" by one member of Congress, Joyce said, "I think the jury considered it serious since they were all convicted."
In fact, ABC News found there was no jury trial of any of the three alleged plotters. None of them were charged with planning an attack on Wall Street. Rather, all three pleaded guilty to charges including providing financial and material support to al Qaeda.
A U.S. official familiar with the case acknowledged that Joyce had "misspoke" about a jury finding.
The official insisted that a terror plot may not seem like a serious threat if it's stopped in the planning stages, as the Stock Exchange targeting was.
"It was, as Deputy Director Joyce stated, in its nascent stages and could have progressed well beyond that if it wasn't for our ability to obtain the FISA material," the official told ABC News.
Describing the charges against one of the plotters, Khalid Ouazzani of Kansas City, the then-United States attorney Beth Phillips, now a federal judge, said, "We have no evidence that Ouazzani engaged in any specific plot against the United States government."
A spokesman, Don Ledford, today added, "We would still stand by that, that he posed no imminent threat to the public."
One current and one former counter-terrorism official told ABC News there may be more to the Hasanoff case than the public record contains, including sensitive intelligence prosecutors chose not to enter into evidence.
Officials said whatever the role of the NSA programs, there is no doubt that Hasanoff and the others were potential threats to the U.S. through their repeated contacts with al Qaeda figures in Yemen.
Authorities said the NSA surveillance programs did first identify Ouazzani as being in contact with al Qaeda leaders in Yemen, and that information helped lead to two other Americans, Hasanoff and Wesam El-Hanafi, who all swore an oath of allegiance to al Qaeda, according to the court documents.
FBI agents were then able to investigate Ouazzani, track his travels to the Middle East and later he became a cooperating witness for the government.
According to the government documents, the New York Stock Exchange plot began in 2008 with a request to Hasanoff to "perform surveillance" for "purposes of planning an attack in the United States."
On August 7, Hasanoff wrote in an email to his al Qaeda coordinator in Yemen, intercepted by the government, "I have visited the tourist locations you asked me about and will report to you after two weeks in detail."
The FBI report says the al Qaeda leader "was not satisfied with the report, and he accordingly disposed of it. (The report apparently lacked sufficient detail about New York Stock Exchange security matters to be as helpful as the Doctor had hoped.)"
The attorney for Hasanoff, David Rhunke, said the idea that the FBI and the NSA would use the alleged plot to justify the surveillance programs is "almost silly."
In his plea to the court ahead of sentencing, Hasanoff said "he deliberately provided nothing beyond what anyone could have learned from Google Earth, a tourist map or brochure." He said there was "no further discussion of surveillance of the NYSE or any other tourist sites after August 2008."
Yet, FBI deputy director Joyce repeatedly cited the case in defending the controversial electronic surveillance. "I sit before you today, humbly, to say these tools have helped us," he said.
Gen. Keith Alexander, the head of the NSA, testified, "The information gathered from these programs provided the US government with critical leads to help prevent over fifty potential terrorist events in more than 20 countries around the world."