Little is publicly known about the two investigations. Lawyers say the FBI questioned an investigator and a classified material analyst for the team representing defendant Ramzi Binalshibh; an investigator for defendant Mustafa al-Hawsawi; and a translator on the team representing Mohammed, who has portrayed himself as the mastermind of the terror attack on Sept. 11, 2001.

James Harrington, a lawyer for Binalshibh, told the court his investigator denied speaking to the FBI and has left his team. „We have had basically a spy within our team for a number of months,“ he said.