Authorities in Senegal are holding a man believed to have played a key role in orchestrating a bomb plot that was foiled when border agents arrested a suspected Algerian terrorist in Port Angeles last month, law enforcement sources said.
Federal agents were traveling to the West African nation to question the man, Mohambedou Ould Slahi, sources said.
A Justice Department source, speaking on condition of anonymity, said the FBI is aware that Slahi had at least one face-to-face contact with Ahmed Ressam, whose Dec. 14 arrest in Port Angeles with a car carrying explosives initiated the international investigation.
Slahi also has been linked to others arrested in the plot, the source said.
Slahi is a brother-in-law of a close lieutenant to Osama bin Laden, the exiled Saudi terrorist who has been charged in the United States with masterminding the bombing of two American embassies in East Africa.
U.S. investigators believe Slahi, while living in Montreal, played a major role in directing a group of Algerians who plotted to enter the United States from Canada at remote border crossings and carry out a terrorist attack, sources said.
"His name came up early on," the Justice Department source said. "There was some question about where he fitted in. Now we know."
Federal agents were led to Slahi through telephone records, which have helped investigators piece together what is believed to be the most serious terrorist threat against the United States since the 1993 World Trade Center bombing in New York.
Ressam, for instance, had the New York telephone number of a man named Abdel Ghani Meskini in his car when he was arrested. Meskini has also been charged.
Federal prosecutors in New York, who have taken the lead role in the case, are considering filing formal charges against Slahi in order to extradite him from Senegal.
Slahi is believed to have worked with Makhtar Haouari, a 31-year-old Algerian living in Montreal who has been indicted in New York on charges he helped direct the bomb plot. Federal prosecutors are seeking his extradition from Canada, where he is being held without bail.
In the New York indictment, prosecutors said Haouari asked Meskini to travel to Seattle in mid-December to assist Ressam.
Haouari and Meskini have been charged in New York with conspiring to support terrorists by trafficking in false U.S. immigration cards and passports of foreign countries.
Meskini provided the FBI with key information about Haouari's actions, Canadian authorities said last week during a court hearing in which Haouari was ordered held.
Authorities in Senegal took Slahi into custody in the past few days at the request of U.S. investigators, sources said.
Slahi fled from Canada shortly after Ressam's arrest, sources said.
Slahi's emergence as a suspect is the strongest link yet to bin Laden and his network, though U.S. investigators cautioned that they have yet to develop evidence directly tying bin Laden to the plot.
Bin Laden is believed to be living in Afghanistan, where U.S. authorities suspect Ressam and other Algerians associated with the Armed Islamic Group have been trained at bin Laden's terrorist camps. The Armed Islamic Group, known by its French initials GIA, is made up of fundamentalist Islamic militants seeking to overthrow Algeria's military-backed regime.
Federal prosecutors have not identified the target of the bomb plot, though law enforcement officials have said Seattle and New York were possible targets.