In a series of pretrial motions, Padilla's lawyers argue that information from Mr. Abu Zubaydah and another confidential source used to justify the May 2002 warrant was the product of torture. They say information obtained through torture cannot be used in court and that any evidence seized from Padilla during his Chicago arrest must be excluded from use at his trial.
Last week, one day before Mr. Bush publicly acknowledged the secret CIA prisons and interrogations, a federal magistrate judge in Miami rejected Padilla's arguments.
US Magistrate Judge Stephen Brown ruled that defense attorneys had failed to offer enough proof concerning the identity and treatment of the confidential sources the government used to justify the warrant.
In addition, Judge Brown ruled that even if the information the confidential sources provided was the product of torture, defense lawyers had presented no evidence that the FBI agent who prepared the warrant application was aware that they had been tortured. Short of a deliberate effort by that agent to intentionally mislead the court, the defense motion must be denied, the magistrate judge ruled.
Padilla's lawyer, Andrew Patel, says the decision is being appealed to US District Judge Marcia Cooke, the trial judge in the Padilla case. He declined any further comment on the case.
In an earlier brief, Mr. Patel wrote: "The government's claim of ignorance appears either to be incredible or the product of conscious avoidance."
In his speech, Bush justified the harsh tactics as essential to prevent terror attacks. But he also asked Congress to formulate special rules so that Abu Zubaydah and 13 other individuals could be tried by military commissions at Guantánamo Bay, Cuba, despite their harsh treatment while in CIA custody.
The special provisions are necessary, in part, because the US criminal justice system excludes coerced statements as too unreliable to present in court. There is also a blanket ban on information obtained through torture.
Bush insists that torture was not used in the CIA operations. But he declined to identify the specific interrogation practices.