WASHINGTON (CNN) -- The FBI sent agents to Guantanamo Bay in 2006 to independently obtain information the CIA had gotten from "high-value" al Qaeda detainees, but without using harsh interrogation techniques, a government official told CNN Tuesday.
More than 300 foreign nationals are being held at the U.S. Navy Base at Guantanamo Bay, Cuba.
The official asked not to be named because information about the questioning is classified.
FBI Director Robert Mueller had told agents to stay out of the CIA interrogations because of concern that the way the information was being obtained would not hold up in a court of law, the official said.
The CIA used harsh interrogation techniques, including waterboarding, during its questioning of three top al Qaeda detainees, CIA Director Michael Hayden said last week.
Waterboarding involves strapping a person to a surface, covering his face with cloth and pouring water on the face to imitate the sensation of drowning. Critics have called it torture.
There are questions about whether testimony gathered through waterboarding would be considered as testimony, said Charles Swift, a former U.S. Navy attorney who represented Osama bin Laden's driver.
The last legal precedent he could find for such a move, he said, was the Spanish Inquisition -- more than 500 years ago.
The objective of the FBI agents was to find out about any role the detainees played in the September 11, 2001, attacks and other activities, the government official said.
The FBI was seeking the same details the CIA had gotten in previous interrogations, the official said.
The captives were read rights similar to Miranda rights by the FBI agents, the official said.
The questioning happened after the detainees had been transferred from CIA custody to a prison facility in Guantanamo Bay, Cuba, the official said.
Five of the men the Pentagon announced it intends to bring charges against are among those high-value detainees. E-mail to a friend